Promethazine Well-documented

Well-documented

Multiple authoritative sources agree on dosing and effects.

5 corroborating sources

1 ROA with full dose ladder

duration data present

toxicity data (PsychonautWiki, PubChem)

Aliases: Phenergan, Promethazine hcl

Summary TripSit PsychonautWiki

Promethazine (commonly sold as Phenergan or Lergigan) is a depressant substance of the phenothiazine class. Alongside codeine, it is popularly known as one of the active two ingredients in "lean". It acts as an antihistamine.

Dose Information PsychonautWiki

ROA	Light	Common	Strong	Heavy
Oral	12.5-25mg	25-50mg	50-100mg	100mg+

Light Common Strong Heavy

Sources

Oral

Dose ladder — PsychonautWiki

Onset, Duration & After-effects TripSit PsychonautWiki

ROA	Onset	Comeup	Peak	Offset	After Effects	Total
Oral	15-30 min	20-60 min	4-8 hrs	3-5 hrs	0-3 hrs	4-8 hrs

Tolerance

Build-up sedative and antiemetic tolerance develops over 1–2 weeks

Reset a few days

Tolerance Decay

Full tolerance 3d Half tolerance 4d Baseline ~5d

Effects Erowid

Aggregated from 12 single-substance Erowid experience reports; 23 Erowid reports where another drug was taken too are left out

Each bar shows the share of analyzed reports whose text mentions that effect — a mention is not always a first-hand experience (fear of an effect or something witnessed can count). Mentions saying the effect did not happen are left out; that check reads keywords, so it can miss some. The shaded band on a bar, and the small range after its number, is the 95% interval: where the share could plausibly be with other reports of the same kind. Fewer reports, wider band. Tap or hover any number for details. The second value is the Bluelight extractor's per-effect confidence; a dash means the row is Erowid-derived, which has no confidence measurement.

Too few reports for bars: these effects come from 12 single-substance Erowid reports, and a bar is drawn only from 20 reports or more. With fewer, a percentage cannot tell a common effect from a rare one. Counts are shown instead. Why 20?

Positive Effects 2

6 of 12 –

3 of 12 –

Adverse Effects 0

Also reported in combinations. In the 23 Promethazine reports where another drug was taken too, 3 (13.0%) mention hospital, emergency services or an overdose, 1 (4.3%) a seizure and 0 (0.0%) psychosis. In the 12 single-substance reports: 2, 1 and 0. These are not in the figures above: they cannot be put down to Promethazine alone, and a mention is not always something that happened to the writer.

Community Trip Reports

Anecdotal first-person accounts from Reddit, Erowid, Bluelight, and Dose.wiki. Click a source to expand. Reports are harm-reduction context, not medical guidance. Tags summarise each author's own verdict — how reports are classified.

Erowid 8 reports 3 positive 5 cautionary visit

I Felt Happy and Sedated positive exp #30807

I took 2 25 mg tabs at 8:30AM....... By 9:15 I had a pleasant, sedated feeling. A kind of euphoric side effect as well, but not like the euphoric sensations of an Opioid. I noticed if I took this at beditme I slept soundly. But by taking it while wide awake, it produced a more noticable lightheadedness.

Few Rewards + Major Side Effect cautionary exp #63928

Okay, Im finally writing in on something that went wrong. Darn. I suppose I couldve prevented the situation by reading up more thoroughly on side effects, but dosages at which these side effects present themselves is not really found anywhere I looked, so maybe not.

Foggy Haze Of Trying To Stay Awake positive exp #83467

Promethazine Fun Sporting a niggling hangover that just wouldnt go away, I started looking for something to take which would dull the hangover or replace the feeling of it with a different feeling all together.

A Full Barrel cautionary exp #43767

I have taken promethazine before, yet in combonation with meperidine in my favorite capsule called Mepergan Forte. Yet my friend recentley was prescribed a bottle of 25 mg promethazine tabs only. Of course he called me up to make a few bucks. That night at around 6 PM I took 3 of the tablets.

Over the Years, Many Times positive exp #103778

A Promethazine Affair My roommate had been having severe stomach issues, thus was prescribed Promethazine for nausea. After about a week of taking them, she came up to me and said 'you have to try these'.

Paranoia, Palpitations and Anxiety cautionary exp #115115

Promethazine Nightmare I have found very few reports or incidences online of such an experience with promethazine hydrochloride. I initially thought my dosage was in line with what was recommended, however from what I can tell, for the high dosage that I took other drugs are usually prescribed alongside it to help coun...

Twitching in My Bed cautionary exp #72494

[Erowid Note: Driving while intoxicated, tripping, or extremely sleep deprived is dangerous and irresponsible because it endangers other people. Don't do it! ] I took four 25 mg pills of promethazine to give my night a kick, and began to feel slightly sedated and relaxed about 40 minutes in.

Just Another Medicine cautionary exp #58712

I've used benzo's very long, and im very tolerant and addicted to them. I wanted to try stopping, but suffered extreme withdrawal syptoms and didnt sleep a couple of days when I tried not taking them, I immedietly went back on them, and my doctor gave me phenergan, or promethazine which is supposedly less addictive and...

Bluelight 2 threads 2 neutral visit

Promethazine 50mg 50mg Codiene 10 10 High neutral

To start off i had 25 drops of nutmeg essentials oil (about .5ml) this morning at about 11:00 After several hours the effects were minimal but still noticabel After little success I found out that promethazine can have phycotic effects when mixed with codiene which is a cough syrup.

First Time 8 Tabs Promethazine 25mg neutral

I've heard promethazine (seasick or allergy pills) can have psychedelic effects much like weed numerous times but only ever used them for their actual purpose taking 1-2 at a time but after an ongoing lack of internet and smoking for 3 months I got extremely bored and decided to give this myth a test.

Pill Identifiers

16 known pill identifiers on record — view imprints, colors, shapes, and images

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Promethazine's nerd page Pharmacology, chemical data, effect profiles, and more

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Helpful Links

📘 Experience Reports 📖 Erowid 📖 TripSit 📖 PsychonautWiki

Import into PsychonautWiki Journal

The PsychonautWiki Journal app includes Promethazine, but its built-in data can be thinner than ours. Importing this file adds a separate "Promethazine (Substance Search)" custom substance with our dose ranges, durations and tolerance, so you can log against whichever you prefer.

⬇ Download import file Import this file as custom substances and you get "Promethazine (Substance Search)" with every route's full dose ladder and timeline, no typing. Works on iOS and Android (v15+); the format is confirmed by the app's developer.

Ranges are harm-reduction guidance, not a prescription.

Report an issue or suggest an edit

Spotted incorrect or dangerous information, have a correction, a new study, or a useful addition for Promethazine? Let us know. Reports are reviewed by moderators — this is not posted publicly.

Promethazine Well-documented Well-documented Multiple authoritative sources agree on dosing and effects. 5 corroborating sources 1 ROA with full dose ladder duration data present toxicity data (PsychonautWiki, PubChem)