KNOW MORE. LOOK AFTER EACH OTHER.
What we know. What remains uncertain. What the myths miss. Clear information without judgment, with references you can check.
Select your drugs & medicines to explore interaction warnings ↗
START WITH THE BIG RISKS
A dangerous blood-pressure drop is the concern. Sildenafil with organic nitrites is contraindicated. A short rush does not mean the interaction is over.
DailyMed — DailyMed: Sildenafil prescribing information — contraindications and interactions ↗FDA — FDA: Nitrite poppers can cause severe injury or death ↗Alcohol, G, opioids, benzodiazepines and sleep medicines can combine to suppress breathing. Ketamine labeling also warns about other CNS depressants.
DailyMed — DailyMed: XYWAV prescribing information and Medication Guide ↗DailyMed — DailyMed: Tramadol — respiratory depression and serotonin syndrome ↗DailyMed — DailyMed: Ketamine hydrochloride — CNS depressant interactions ↗Some combinations can cause severe toxicity. MAOI and serotonin-active medicine warnings depend on the drug. Do not treat every antidepressant as interchangeable or take more to overcome a muted high.
DailyMed — DailyMed: DESOXYN prescribing information — interactions ↗Farré et al. (2007) — Farré et al. (2007): MDMA–paroxetine randomized crossover study ↗Ritonavir and cobicistat can affect drug metabolism. Documented and predicted interactions differ by pair. Liverpool rates the meth/ritonavir and MDMA/darunavir-cobicistat assessments very low evidence; that uncertainty is not reassurance.
Liverpool — Liverpool: Ritonavir + methamphetamine ↗Liverpool — Liverpool: Darunavir/cobicistat + MDMA ↗University of Liverpool HIV Drug Interactions checker — University of Liverpool HIV Drug Interactions checker ↗Include prescriptions, PrEP or HIV treatment, OTC cold/allergy/sleep medicines, supplements, alcohol and recreational drugs. Use the actual medicine names. Do not skip, stop or change prescribed treatment to make room for drug use. A pharmacist or prescriber can assess the exact combination and your health history.
Open Liverpool’s HIV interaction checker ↗ · Explore interaction warnings ↗
This is a guide to selected hazards, not a complete pair checker, dose calculator, or prediction of a multi-drug mixture.
THE SUBSTANCE GUIDE
26 of 26 entries shown. Street names can refer to more than one substance.
01 / Stimulant
Crystal meth · Tina · ice · speed (an ambiguous street name)
Can increase alertness, heart rate and blood pressure. Serious harms include overheating, heart problems, stroke, paranoia and psychosis. Dependence can develop; a difficult comedown does not by itself establish a use disorder.NIDA — NIDA: Methamphetamine research report ↗
Prescription methamphetamine labeling warns about MAO inhibitors and serotonergic medicines, including SSRIs, SNRIs and tramadol. These warnings identify hazards, not a safe street dose. Ritonavir may increase exposure; Liverpool rates that prediction very low evidence.DailyMed — DailyMed: DESOXYN prescribing information — interactions ↗Liverpool — Liverpool: Ritonavir + methamphetamine ↗
Street strength, ingredients, duration and an individual's risk cannot be predicted from appearance or a previous experience. Some interaction warnings come from prescription labeling or pharmacology rather than studies of street use.
“If I have mixed it before without problems, the combination is safe.”
Prior uneventful use does not remove cardiovascular or psychiatric risk. Alcohol or a sedative does not make a stimulant harmless.NIDA — NIDA: Methamphetamine research report ↗NIAAA — NIAAA: Alcohol–medication interactions ↗
02 / Stimulant
4-MMC · m-cat · meow meow · bath salts (a broad category)
Reported toxic effects include a rapid heartbeat, high blood pressure, agitation, overheating and seizures. Different cathinones have different pharmacology; findings for one cannot be applied to all.ACMD — ACMD: Synthetic cathinones, updated harms assessment (2025) ↗
Other stimulants can compound cardiovascular stress. Serotonin toxicity is a concern with serotonergic cathinones and other serotonin-active substances; the risk for a specific medicine pair is often not measured in humans.ACMD — ACMD: Synthetic cathinones, updated harms assessment (2025) ↗
Human interaction studies and long-term data are limited. A product sold as 4-MMC or 3-MMC may contain another substance; no reliable universal dose or redosing interval follows from the name.
“A research chemical or legal-looking packet has been tested for safety.”
Marketing and packaging do not establish identity, purity or safety. Toxicity reports and deaths have involved synthetic cathinones.ACMD — ACMD: Synthetic cathinones, updated harms assessment (2025) ↗
03 / Depressant
G · Gina · liquid ecstasy (not MDMA)
Can cause sudden unconsciousness, vomiting and dangerous breathing suppression. GBL and 1,4-BD are converted to GHB in the body. Frequent use can produce dependence and life-threatening withdrawal within hours of stopping.DailyMed — DailyMed: XYWAV prescribing information and Medication Guide ↗ACMD — ACMD: GHB, GBL and related compounds — harms and withdrawal ↗
Avoid combining with alcohol, opioids, benzodiazepines, sleep medicines or other sedating substances. Oxybate labeling documents risks including breathing suppression, coma and death with CNS depressants; it does not validate illicit mixtures.DailyMed — DailyMed: XYWAV prescribing information and Medication Guide ↗
A volume in milliliters does not tell you the amount of drug without a known concentration. No fixed waiting period, bottle size or GBL-to-GHB multiplier makes street use safe.
“They are only having a G nap; wait for them to wake up.”
Call 911 immediately if they cannot be woken. Do not assume sleep. If using G frequently or around the clock, get urgent medical help to plan withdrawal rather than stopping alone.DailyMed — DailyMed: XYWAV prescribing information and Medication Guide ↗ACMD — ACMD: GHB, GBL and related compounds — harms and withdrawal ↗
04 / Dissociative
K · special K
Can cause dissociation and impaired awareness. Medical ketamine is an anesthetic; clinical use includes screening and monitoring. Serious risks include sedation, blood-pressure changes and breathing problems. Repeated recreational use has been associated with severe bladder injury.DailyMed — DailyMed: Ketamine hydrochloride — CNS depressant interactions ↗Shahani et al. (2007) — Shahani et al. (2007): Ketamine-associated ulcerative cystitis ↗
Ketamine with opioids, benzodiazepines or other CNS depressants, including alcohol, can cause profound sedation, breathing suppression, coma or death. Medical use does not establish that a recreational mixture is safe.DailyMed — DailyMed: Ketamine hydrochloride — CNS depressant interactions ↗
Street purity and individual effects are uncertain. Evidence from supervised treatment cannot establish a safe recreational amount or mixture.
“Because clinicians use it, a K-hole is a safe state to leave someone in.”
Medical use involves monitoring. Call 911 immediately if they cannot be woken, regardless of the drug's medical uses.FDA — FDA: Ketamine safety warning — anesthesia and compounded products ↗
05 / Vasodilator
Alkyl nitrites · amyl / isopropyl / pentyl nitrite
Nitrites can sharply lower blood pressure and impair the blood's ability to carry oxygen (methemoglobinemia). Swallowing or inhaling them can cause serious injury; liquid can burn tissue.FDA — FDA: Nitrite poppers can cause severe injury or death ↗
Do not combine with sildenafil (Viagra) or similar erection medicines. Sildenafil labeling contraindicates organic nitrites because of dangerous blood-pressure reduction. Prescription nitrates and riociguat are also contraindicated with sildenafil.DailyMed — DailyMed: Sildenafil prescribing information — contraindications and interactions ↗
Products vary in contents. A short rush does not establish a short interaction window. This guide cannot provide a safe waiting time between poppers and an erection medicine.
“Blue lips are an ordinary poppers side effect I can ignore.”
Blue or gray lips, breathing trouble or collapse can signal a medical emergency. Call 911. Do not dismiss these signs or assume fresh air alone will fix them.FDA — FDA: Nitrite poppers can cause severe injury or death ↗
06 / Medication
Sildenafil / Viagra · tadalafil / Cialis · sexual enhancement supplements
Prescription erection medicines affect blood flow; they do not make drug combinations safe. Sildenafil can cause low blood pressure and prolonged erections. An erection lasting more than four hours requires urgent medical care.DailyMed — DailyMed: Sildenafil prescribing information — contraindications and interactions ↗
Sildenafil must not be used with organic nitrites/nitrates or riociguat. Alpha blockers and blood-pressure medicines can increase hypotension risk. Ritonavir substantially increases sildenafil exposure; a pharmacist must check the exact prescription.DailyMed — DailyMed: Sildenafil prescribing information — contraindications and interactions ↗
Unregulated products may contain undeclared drugs or variable amounts. Each erection medicine has different duration and labeling; do not copy sildenafil timing advice to tadalafil.
“Herbal means weaker and safer.”
FDA testing has found undeclared sildenafil in products sold for sexual enhancement. A natural claim cannot exclude prescription-drug interactions.FDA — FDA: Hidden sildenafil in a sexual enhancement product ↗
07 / Stimulant
Ecstasy · Molly · E (names do not confirm contents)
Can cause overheating and dangerously low blood sodium. Drinking excessive water is also dangerous; hydration alone does not prevent toxicity.NHS inform — NHS inform: MDMA (ecstasy) ↗
MDMA with MAOIs has caused fatal serotonin toxicity. Antidepressant effects vary by drug. In a small controlled study, paroxetine reduced some felt effects while increasing MDMA exposure. That is not evidence of a safe combination. Liverpool predicts a possible interaction with darunavir/cobicistat, rated very low evidence.Vuori et al. (2003) — Vuori et al. (2003): Deaths after MDMA and moclobemide ↗Farré et al. (2007) — Farré et al. (2007): MDMA–paroxetine randomized crossover study ↗Liverpool — Liverpool: Darunavir/cobicistat + MDMA ↗
Rare severe outcomes and street mixtures are not captured by small studies in screened volunteers. Do not assume every antidepressant has the same interaction, or stop prescribed treatment to use MDMA.
“If my antidepressant blunts the high, I should take more MDMA.”
Felt effects and drug concentration can move in different directions. Taking more to overcome blunting can add risk; the paroxetine trial does not establish a safe redose.Farré et al. (2007) — Farré et al. (2007): MDMA–paroxetine randomized crossover study ↗
08 / Stimulant
Coke · blow · rock
Can cause heart attack, stroke, seizures and overheating. Smoking, snorting or injecting does not eliminate these risks.NHS inform — NHS inform: Cocaine ↗
Alcohol and cocaine together create cocaethylene and increase risk. Other stimulants add cardiovascular stress. Tell the clinician about both prescribed stimulants and recreational substances.NHS inform — NHS inform: Cocaine ↗
Purity, adulterants and personal susceptibility vary. We cannot give a reliable individual overdose probability from a street name, appearance or amount.
“Cocaine sobers me up after alcohol.”
Feeling more alert does not undo alcohol impairment. Combining them introduces additional toxicity.NHS inform — NHS inform: Cocaine ↗NIAAA — NIAAA: Alcohol–medication interactions ↗
09 / Depressant
Heroin · fentanyl · oxycodone · counterfeit pain pills
Opioids can suppress breathing. Illicit fentanyl may be present in other drugs or counterfeit pills and cannot be identified by sight, smell or taste.CDC — CDC: Fentanyl and limits of test strips ↗
Combining opioids with benzodiazepines, alcohol or other CNS depressants can cause profound sedation, coma and death. Tramadol also has serotonin-syndrome interactions with serotonin-active medicines.DailyMed — DailyMed: Tramadol — respiratory depression and serotonin syndrome ↗FDA — FDA: Benzodiazepine boxed warnings, dependence and withdrawal ↗
A negative fentanyl strip does not guarantee safety or exclude all fentanyl-like drugs. It does not measure a safe dose or test for every adulterant.
“Naloxone reverses every kind of overdose.”
Naloxone reverses opioid effects; it does not directly reverse other drugs. Call 911 immediately if they cannot be woken and follow the dispatcher. Give naloxone for possible opioid exposure without delaying the call or CPR. More than one dose may be needed; remain with the person.CDC — CDC: Five things to know about naloxone ↗
10 / Depressant
Alprazolam / Xanax · diazepam / Valium · clonazepam · Z-drugs
Benzodiazepines can cause dependence even when prescribed. Abrupt withdrawal or rapid reduction can cause life-threatening seizures. Sleep medicines differ; a pill's appearance does not establish its contents.FDA — FDA: Benzodiazepine boxed warnings, dependence and withdrawal ↗CDC — CDC: Fentanyl and limits of test strips ↗
Alcohol, opioids and other sedatives increase risks of severe sedation and breathing suppression. Do not use an unprescribed sedative to manage a comedown or withdrawal.FDA — FDA: Benzodiazepine boxed warnings, dependence and withdrawal ↗NIAAA — NIAAA: Alcohol–medication interactions ↗
A counterfeit tablet may not contain the named medicine. A safe taper depends on the drug and individual; this guide cannot supply one.
“Quitting cold turkey is always the safest choice.”
Dependence needs a clinician-guided plan. FDA warns against abrupt discontinuation or rapid dose reduction of benzodiazepines.FDA — FDA: Benzodiazepine boxed warnings, dependence and withdrawal ↗
11 / Depressant
Beer · wine · spirits
Alcohol can interact with both prescription and over-the-counter medicines. Interactions can occur even when substances are taken at different times.NIAAA — NIAAA: Alcohol–medication interactions ↗
Opioids, benzodiazepines and sleep medicines increase sedation and breathing risks. Sedating antihistamines can worsen impairment. Alcohol can also complicate diabetes treatment and raise gastrointestinal bleeding risk with NSAIDs such as ibuprofen.NIAAA — NIAAA: Alcohol–medication interactions ↗
There is no universal number of drinks or waiting interval that clears every medicine. Exact medication, dose, health conditions and drinking pattern matter.
“An over-the-counter medicine cannot interact seriously with alcohol.”
OTC availability is not an interaction clearance. Check cold, allergy, sleep and pain products by active ingredient with a pharmacist.NIAAA — NIAAA: Alcohol–medication interactions ↗
12 / Cannabinoid
Weed · THC · edibles · concentrates
Can impair coordination, reaction time, judgment and driving skills. Feeling comfortable or experienced does not establish fitness to drive.CDC — CDC: Cannabis and driving ↗
Alcohol plus cannabis can increase impairment. Avoid driving after use and ask a pharmacist about the exact cannabis product and medicines; this page does not clear THC or CBD combinations.CDC — CDC: Cannabis and driving ↗
Different formulations and THC/CBD content limit generalization. This entry does not cover synthetic cannabinoids such as K2/Spice, which are different drugs.
“If it is legal or prescribed, driving after use is safe.”
Legal status and a prescription do not remove driving impairment.CDC — CDC: Cannabis and driving ↗
13 / Psychedelic
Mushrooms · shrooms · acid · classic psychedelics
Can substantially alter perception and mood. Psilocybin can cause panic, increased heart rate and blood pressure, and psychiatric harms; mushroom misidentification can cause fatal poisoning.NIH — NIH: Psychedelic and dissociative drugs ↗NCCIH — NCCIH: Psilocybin — safety, evidence and research gaps ↗
Interactions with psychiatric medicines remain incompletely understood. Do not stop antidepressants, lithium or other prescribed treatment to prepare for a trip; ask your prescriber to evaluate the specific combination.NCCIH — NCCIH: Psilocybin — safety, evidence and research gaps ↗
Results from supported, screened clinical trials do not establish safety for unsupervised use. Microdosing safety and effectiveness remain uncertain; psilocybin findings cannot simply be transferred to LSD.
“Natural mushrooms or microdoses are proven safe treatments.”
Natural origin does not prevent harm. Research signals of benefit have limits and do not establish a safe self-treatment regimen.NCCIH — NCCIH: Psilocybin — safety, evidence and research gaps ↗
14 / Inhalant
Laughing gas · whippets · chargers
Recreational inhalation can cause oxygen deprivation, loss of consciousness and serious injury. Repeated use can inactivate vitamin B12 and damage the nervous system.FDA — FDA: Do not inhale recreational nitrous oxide products ↗Case report (2023) — Case report (2023): Functional B12 deficiency after nitrous oxide use ↗
Alcohol and other intoxicants add uncertainty and impairment. A complete recreational-drug interaction map is unavailable; absence of a listed interaction is not clearance.FDA — FDA: Do not inhale recreational nitrous oxide products ↗
There is no validated safe recreational frequency or supplement regimen. A single case report demonstrates a possible harm, not how often it occurs.
“Taking B12 makes continued nitrous use safe.”
Supplementation cannot be treated as protection while exposure continues. New numbness, weakness or walking difficulty needs prompt medical assessment and disclosure of nitrous use.Case report (2023) — Case report (2023): Functional B12 deficiency after nitrous oxide use ↗FDA — FDA: Do not inhale recreational nitrous oxide products ↗
15 / Psychedelic
DMT · dimethyltryptamine · ayahuasca preparations
N,N-DMT is a psychedelic. It is chemically distinct from 5-MeO-DMT; do not treat the names as interchangeable.NIH — NIH: Psychedelic and dissociative drugs ↗Brush, Bird & Boyer (2004) — Brush, Bird & Boyer (2004): 5-MeO-DMT + harmaline poisoning ↗
Ayahuasca may include MAOI-active ingredients such as harmaline. Those ingredients change the interaction question. Tell the pharmacist what is in the whole preparation, including prescription and supplement ingredients.DMT/harmine pharmacology in healthy participants (2025) — DMT/harmine pharmacology in healthy participants (2025) ↗
Human data for individual preparations and medicine combinations are limited. We do not infer a safe interaction from a DMT-only study.
“DMT and Bufo are simply two names for the same drug.”
N,N-DMT and 5-MeO-DMT are different chemicals; a published poisoning involved 5-MeO-DMT and harmaline.Brush, Bird & Boyer (2004) — Brush, Bird & Boyer (2004): 5-MeO-DMT + harmaline poisoning ↗
16 / Psychedelic
Toad secretion · toad venom · 5-MeO-DMT (not N,N-DMT)
A human case report documents severe poisoning after 5-MeO-DMT with harmaline, an MAOI. Toad secretion is not a standardized prescription product.Brush, Bird & Boyer (2004) — Brush, Bird & Boyer (2004): 5-MeO-DMT + harmaline poisoning ↗
Do not combine 5-MeO-DMT with MAOIs. Evidence for many other medication combinations is limited; an individual pharmacist review is essential.Brush, Bird & Boyer (2004) — Brush, Bird & Boyer (2004): 5-MeO-DMT + harmaline poisoning ↗
One poisoning case cannot establish the incidence of harm or a safe dose. N,N-DMT data cannot clear 5-MeO-DMT mixtures.
“Natural toad secretion is safer than a synthetic drug.”
Natural origin does not remove pharmacological hazards. The reported interaction illustrates why the exact substance matters.Brush, Bird & Boyer (2004) — Brush, Bird & Boyer (2004): 5-MeO-DMT + harmaline poisoning ↗
17 / Opioid-active product
Mitragynine · 7-hydroxymitragynine · extracts
FDA identifies serious risks including liver injury, seizures and substance use disorder. Concentrated 7-OH products differ from traditional leaf products.FDA — FDA: Kratom and concentrated 7-OH products ↗
Medication interactions require individual review. Other opioid-active and sedating products raise concern; this guide has not established pair-specific risks for each kratom mixture.FDA — FDA: Kratom and concentrated 7-OH products ↗
Composition varies across leaf, extracts and concentrated products. The absence of a quantified interaction is not evidence of safety.
“A supplement or smoke-shop product is a proven opioid-withdrawal treatment.”
There is no FDA-approved kratom treatment. Do not replace prescribed treatment based on a product claim.FDA — FDA: Kratom and concentrated 7-OH products ↗
18 / Synthetic cannabinoid
K2 · Spice · synthetic marijuana (not cannabis)
Clinical surveillance documents agitation, delirium, coma, seizures and severe illness. Products contain diverse chemicals; they are not equivalent to THC.CDC MMWR — CDC MMWR: Acute poisonings from synthetic cannabinoids, 2010–2015 ↗
Multiple-substance poisonings occur, but surveillance cannot establish a precise risk for every pair. Treat unknown mixtures as unreviewed, not compatible.CDC MMWR — CDC MMWR: Acute poisonings from synthetic cannabinoids, 2010–2015 ↗
The chemical and concentration may change between products or batches. Cannabis interaction findings cannot simply be applied to K2/Spice.
“Synthetic marijuana is just another kind of weed.”
The name is misleading: different chemicals and serious toxicity require a separate assessment.CDC MMWR — CDC MMWR: Acute poisonings from synthetic cannabinoids, 2010–2015 ↗
19 / Sedative
Tranq · veterinary sedative · drug-supply adulterant
Can slow breathing and heart rate and lower blood pressure. Exposure is associated with serious wounds. It is not approved for human use.CDC — CDC: Xylazine and overdose response ↗
Xylazine mixed with opioids such as fentanyl is especially dangerous. Naloxone does not directly reverse xylazine, but should still be given for possible opioid exposure.CDC — CDC: Xylazine and overdose response ↗
People may not know it is present. Persistent sedation after naloxone is not a reason to leave someone or delay breathing support.
“Naloxone is pointless if tranq might be involved.”
Call 911 immediately if they cannot be woken. Give naloxone for possible opioid exposure without delaying the call or CPR; follow the dispatcher. Opioid effects may coexist with ongoing xylazine effects.CDC — CDC: Xylazine and overdose response ↗CDC — CDC: Five things to know about naloxone ↗
20 / Medication
Zolpidem / Ambien · zopiclone · sleeping tablets
Zolpidem can impair alertness and cause serious complex sleep behaviors. Sleep medicines are not all the same drug class.DailyMed — DailyMed: Zolpidem — CNS depressant effects and interactions ↗
Alcohol and other CNS depressants can add to zolpidem impairment. Opioid combinations raise respiratory concerns; oxybate labeling contraindicates sedative hypnotics.DailyMed — DailyMed: Zolpidem — CNS depressant effects and interactions ↗DailyMed — DailyMed: XYWAV prescribing information and Medication Guide ↗
This entry does not classify every sedating supplement or sleep product. Use the exact active ingredient.
“A sleeping pill is a safe way to end any stimulant session.”
Adding a sedative does not establish safety and may add dangerous impairment. Do not self-treat a comedown with unprescribed sleep medication.DailyMed — DailyMed: Zolpidem — CNS depressant effects and interactions ↗
21 / Medication
Sertraline · fluoxetine · escitalopram · paroxetine
SSRIs affect serotonin. Sertraline labeling warns about serotonin syndrome and discontinuation symptoms. Specific drugs differ in metabolism and duration.DailyMed — DailyMed: Sertraline — serotonin toxicity and discontinuation ↗
MAOIs are contraindicated with sertraline. Methamphetamine labeling warns about serotonergic medicines. Paroxetine can blunt some MDMA effects while increasing MDMA exposure in a small trial.DailyMed — DailyMed: Sertraline — serotonin toxicity and discontinuation ↗DailyMed — DailyMed: DESOXYN prescribing information — interactions ↗Farré et al. (2007) — Farré et al. (2007): MDMA–paroxetine randomized crossover study ↗
These findings do not establish the risk of every SSRI with every street drug. They do not justify abruptly stopping an antidepressant.
“Skipping one tablet removes all interaction risk.”
Medicine effects can persist, and stopping treatment can cause harm. Medication changes require your prescriber.DailyMed — DailyMed: Sertraline — serotonin toxicity and discontinuation ↗
22 / Medication
Venlafaxine · duloxetine · desvenlafaxine
SNRIs affect serotonin and norepinephrine. They belong in a medication interaction review, including with prescribed and recreational stimulants.DailyMed — DailyMed: DESOXYN prescribing information — interactions ↗DailyMed — DailyMed: Tramadol — respiratory depression and serotonin syndrome ↗
Methamphetamine and tramadol labeling identify SNRIs among serotonin-active medicines that can increase serotonin-syndrome risk. These are specific warnings, not a complete map of recreational mixtures.DailyMed — DailyMed: DESOXYN prescribing information — interactions ↗DailyMed — DailyMed: Tramadol — respiratory depression and serotonin syndrome ↗
Individual SNRIs and combinations differ. This guide cannot estimate a safe dose or individual probability of serotonin toxicity.
“All antidepressants have exactly the same interactions.”
Class labels are a starting point. Give the pharmacist the specific drug name and the full mixture.DailyMed — DailyMed: DESOXYN prescribing information — interactions ↗DailyMed — DailyMed: Sertraline — serotonin toxicity and discontinuation ↗
23 / Medication / plant alkaloid
Phenelzine · tranylcypromine · harmaline / harmine
MAO inhibition can produce serious interactions. Some prescription medicines and some plant preparations have this action.DailyMed — DailyMed: DESOXYN prescribing information — interactions ↗Brush, Bird & Boyer (2004) — Brush, Bird & Boyer (2004): 5-MeO-DMT + harmaline poisoning ↗
Methamphetamine with MAOIs is contraindicated. Sertraline has an MAOI contraindication. Severe poisoning has been reported with harmaline plus 5-MeO-DMT.DailyMed — DailyMed: DESOXYN prescribing information — interactions ↗DailyMed — DailyMed: Sertraline — serotonin toxicity and discontinuation ↗Brush, Bird & Boyer (2004) — Brush, Bird & Boyer (2004): 5-MeO-DMT + harmaline poisoning ↗
Drug-specific effects may persist after stopping. No generic waiting-time rule here clears recreational use.
“Plant-derived MAOIs do not count as medication interactions.”
Harmaline was the MAOI in a published 5-MeO-DMT poisoning. Tell clinicians about plant preparations and supplements.Brush, Bird & Boyer (2004) — Brush, Bird & Boyer (2004): 5-MeO-DMT + harmaline poisoning ↗
24 / Medication
Neurontin · Lyrica · gabapentinoids
FDA warns of serious breathing problems in people with respiratory risk factors, including other CNS depressants or impaired lung function.FDA — FDA: Gabapentin and pregabalin — serious breathing problems ↗
Opioids and other depressants, including benzodiazepines, can increase breathing and sedation risks. Do not treat gabapentinoids as harmless add-ons.FDA — FDA: Gabapentin and pregabalin — serious breathing problems ↗
Risk depends on the exact prescription, other drugs and health conditions. This guide does not recommend a dose adjustment.
“A nerve-pain medicine cannot contribute to overdose.”
Gabapentinoids can contribute to serious breathing problems, especially in high-risk combinations.FDA — FDA: Gabapentin and pregabalin — serious breathing problems ↗
25 / Medication
Nitroglycerin · isosorbide
Prescription nitrates affect blood vessels and must be included when reviewing erection medicines. They are distinct from recreational nitrites, but both matter for these interactions.DailyMed — DailyMed: Sildenafil prescribing information — contraindications and interactions ↗DailyMed — DailyMed: Tadalafil for erectile dysfunction — interactions ↗
Organic nitrates are contraindicated with sildenafil and tadalafil. Tell emergency clinicians about erection medicines and timing so they can choose treatment safely.DailyMed — DailyMed: Sildenafil prescribing information — contraindications and interactions ↗DailyMed — DailyMed: Tadalafil for erectile dysfunction — interactions ↗
The exact drug and clinical situation matter. This page does not provide a self-managed waiting period or tell you to change heart treatment.
“Poppers are the only blood-pressure interaction to disclose.”
Prescription heart medicines also matter. Include them in the full list for your pharmacist and emergency team.DailyMed — DailyMed: Sildenafil prescribing information — contraindications and interactions ↗
26 / Medication
Norvir · Tybost · boosters in some combination regimens
These medicines affect metabolism and can change exposure to other drugs. A combination tablet may contain a booster; check all active ingredients.Liverpool — Liverpool: Ritonavir + methamphetamine ↗Liverpool — Liverpool: Darunavir/cobicistat + MDMA ↗University of Liverpool HIV Drug Interactions checker — University of Liverpool HIV Drug Interactions checker ↗
Ritonavir increases sildenafil exposure. Predicted methamphetamine/ritonavir and MDMA/darunavir-cobicistat interactions have very low evidence in Liverpool. Check the exact regimen rather than assuming all HIV treatment behaves the same way.DailyMed — DailyMed: Sildenafil prescribing information — contraindications and interactions ↗Liverpool — Liverpool: Ritonavir + methamphetamine ↗Liverpool — Liverpool: Darunavir/cobicistat + MDMA ↗
Predicted exposure changes do not quantify a safe street dose. The checker does not replace a pharmacist or HIV clinician.
“I should stop HIV medicines before using recreational drugs.”
Do not interrupt prescribed treatment based on this guide. Ask your HIV clinician or pharmacist to review the exact regimen and substances.University of Liverpool HIV Drug Interactions checker — University of Liverpool HIV Drug Interactions checker ↗
CONFIDENCE SHOULD MATCH THE DATA
Strong support for a medicine’s listed contraindications and warnings. Prescription formulations and monitored care do not establish safe street doses or mixtures.
A controlled study can show an interaction under its specific conditions. Small samples may miss rare harm. Case reports identify possible hazards but cannot tell us how common they are.
Some interactions are predicted from metabolism rather than measured directly. We label that uncertainty, including Liverpool’s very-low-evidence ratings.
No study, no listed warning, or no matching search result does not establish safety. This guide covers selected substances and hazards; emerging drugs and mixtures may be missing.
Sources checked means the cited material was consulted for this version. It does not mean independent clinical peer review, endorsement by a linked organization, or a guarantee of safety.
TRANSPARENT SOURCE REVIEW
The Trade chemsex page was the starting point, not proof of its own claims. We reviewed its substantive drug sections and safety advice. The notes below summarize how those claims were handled; local service listings, legal claims and linked websites are outside this clinical review.
Qualify. Effects and recovery vary. Avoid a universal duration or suggestion that psychosis must be short-lived. Repeated use is not required for acute harm; dependence and withdrawal are distinct from an individual comedown.
NIDA — NIDA: Methamphetamine research report ↗Replace. Lack of an obvious immediate reaction is not evidence that mixing is safe. Name cardiovascular stress and medicine-specific interaction warnings.
NIDA — NIDA: Methamphetamine research report ↗DailyMed — DailyMed: DESOXYN prescribing information — interactions ↗NIAAA — NIAAA: Alcohol–medication interactions ↗Retain the harm-reduction principle; localize access. Do not carry over a claim that every U.K. service offers equipment to a U.S. audience. Use the site's local service resources. CDC supports sterile injection equipment and syringe services to reduce HIV and hepatitis transmission.
CDC — CDC: Infection prevention and syringe services ↗Qualify. Stimulant toxicity is supported. The original explanation is simplified; hydration is not the whole risk, and cathinone identity and human interaction evidence are uncertain.
ACMD — ACMD: Synthetic cathinones, updated harms assessment (2025) ↗Replace reassuring generalizations. Similar felt effects do not mean identical brain mechanisms or predictable duration. Lack of a typical hangover or an erection does not indicate safety.
DailyMed — DailyMed: XYWAV prescribing information and Medication Guide ↗ACMD — ACMD: GHB, GBL and related compounds — harms and withdrawal ↗Do not reproduce as a dosing protocol. Unknown concentration and individual factors prevent a safe milliliter amount or universal redosing interval. GHB, GBL and 1,4-BD are not interchangeable products.
ACMD — ACMD: GHB, GBL and related compounds — harms and withdrawal ↗DailyMed — DailyMed: XYWAV prescribing information and Medication Guide ↗Retain and strengthen. Breathing suppression and coma are established hazards. Add potentially life-threatening withdrawal and urgent assessment for unresponsiveness.
DailyMed — DailyMed: XYWAV prescribing information and Medication Guide ↗ACMD — ACMD: GHB, GBL and related compounds — harms and withdrawal ↗Retain core risk, remove normalization of use for painful sex. Medical anesthesia does not establish recreational safety. Urinary harms are recognized; see the clinical bladder study linked below.
DailyMed — DailyMed: Ketamine hydrochloride — CNS depressant interactions ↗Shahani et al. (2007) — Shahani et al. (2007): Ketamine-associated ulcerative cystitis ↗Correct nitrites versus nitrates. Do not normalize blue lips: impaired oxygen carriage can be life-threatening. Liquid contact can injure tissue. U.K. legal assertions are outside this U.S. clinical guide.
FDA — FDA: Nitrite poppers can cause severe injury or death ↗Correct. The major interaction is amplified blood-pressure reduction, rather than blood being sent to different body parts. Sildenafil with organic nitrites is contraindicated.
DailyMed — DailyMed: Sildenafil prescribing information — contraindications and interactions ↗Qualify against the exact product label. Do not invent blanket disease contraindications or describe herbal products as reliably weaker. Hidden prescription ingredients have been confirmed.
DailyMed — DailyMed: Sildenafil prescribing information — contraindications and interactions ↗FDA — FDA: Hidden sildenafil in a sexual enhancement product ↗Retain the nonjudgmental approach. Intoxication can affect decision-making; someone unconscious cannot consent. Trade's local clinic schedules and service availability have not been independently verified and are not presented as U.S. referrals.
Trade — Trade: Chem Sex (Drugs and Sex) — starting page reviewed ↗CHECK THE ORIGINALS
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