I first started taking recreational drugs approximately a year and a half ago. Though my experiences since then have been varied and I consider them to be quite an important portion of my life, both in the area of personal development and in garnering a rich history of enjoyable memories.
GBL
Well-documented
Well-documented
Multiple authoritative sources agree on dosing and effects.
- 5 corroborating sources
- 1 ROA with full dose ladder
- duration data present
- 29 combo interactions documented
- toxicity data (PsychonautWiki, PubChem)
Well-documented
Multiple authoritative sources agree on dosing and effects.
- 5 corroborating sources
- 1 ROA with full dose ladder
- duration data present
- 29 combo interactions documented
- toxicity data (PsychonautWiki, PubChem)
Aliases: Gamma-bl, Blue nitro, Revivarant, Renewtrient, 1,4-lactone
Summary
GBL is a prodrug rapidly converted to GHB in the body and is significantly more potent by volume than GHB. Accurate dosing with a syringe is critical as doses are measured in single milliliters. Overdose risk is high and can result in loss of consciousness, respiratory depression, and death, especially when combined with other depressants.
Dose Information
| ROA | Light | Common | Strong | Heavy |
|---|---|---|---|---|
| Oral BA ~95% | 0.3-0.9ml | 0.9-1.5ml | 1.5-2ml | 2ml+ |
Light
Common
Strong
Heavy
Sources
Oral
Dose ladder — dose.wikiOnset, Duration & After-effects
| ROA | Onset | Comeup | Peak | Offset | Total |
|---|---|---|---|---|---|
| Oral | 10-19 min | 10-30 min | 30-90 min | 1-2 hrs | 1.5-2.5 hrs |
Tolerance
Build-up
develops rapidly (prodrug for GHB — same tolerance profile)
Reset
Falls after you stop, at a rate that varies from person to person. If you've been using regularly, cut down gradually with medical help rather than stopping suddenly.
No tolerance chart. Our decay curves for these drugs were estimates, and a curve can make tolerance look longer-lasting than it is, which is the dangerous direction.
How fast tolerance to these drugs fades after a break has not been measured well enough to draw, so don't count on a dose you used to take still being safe: after time off, start with a much smaller amount and don't use alone. Mixing sedatives with each other, with alcohol or with opioids sharply raises the risk of a fatal overdose. If you've been using regularly, don't stop suddenly: withdrawal from benzodiazepines, alcohol or GHB/GBL can cause seizures or delirium, so get medical help to cut down gradually. With GHB and GBL, tolerance drops after you stop, so the amount you used to take can cause an overdose, and the gap between the dose you want and an overdose is small and hard to judge.
Sources: FRANK: benzodiazepines · Alcohol and Drug Foundation: GHB · FDA 2020: benzodiazepine boxed warning · FDA 2019: gabapentinoids and breathing · NHS: alcohol use disorder · FRANK: GHB
Cross-Tolerances
Effects
Aggregated from 42 single-substance Erowid experience reports; 38 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.
Effect glossary — · full glossary
Positive Effects 9
38.1% (95% interval 25 to 53 percent)
–
38.1% (95% interval 25 to 53 percent)
–
23.8% (95% interval 14 to 38 percent)
–
23.8% (95% interval 14 to 38 percent)
–
21.4% (95% interval 12 to 36 percent)
–
14.3% (95% interval 7 to 28 percent)
–
9.5% (95% interval 4 to 22 percent)
–
9.5% (95% interval 4 to 22 percent)
–
7.1% (95% interval 2 to 19 percent)
–
Adverse Effects 7
47.6% (95% interval 33 to 62 percent)
–
23.8% (95% interval 14 to 38 percent)
–
23.8% (95% interval 14 to 38 percent)
–
9.5% (95% interval 4 to 22 percent)
–
9.5% (95% interval 4 to 22 percent)
–
9.5% (95% interval 4 to 22 percent)
–
7.1% (95% interval 2 to 19 percent)
–
Also reported in combinations. In the 38 GBL reports where another drug was taken too, 10 (26.3%) mention hospital, emergency services or an overdose, 3 (7.9%) a seizure and 2 (5.3%) psychosis. In the 42 single-substance reports: 26.2%, 7.1% and 9.5%. These are not in the figures above: they cannot be put down to GBL alone, and a mention is not always something that happened to the writer.
Combinations
Cross-Check GBL with another substanceCommunity 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 2 positive 1 neutral 5 cautionary visit
Always had trouble sleeping, so used to drink a beer or 2 to help me sleep. Then, after realising I`d piled weight on, looked for a substitute, got into legal stims, which doubled the insomnia problem. Tried 1ml of Gbl the first time, loved it, and had a nice relaxed sleep.
Some time around August last year I acquired a steady source for liter quantities of gbl. This source was out of the country and the price was good. Since this date we have had a stready supply until now, why? because I am not getting any more... I have read many great things about gbl and ghb...
Its 2:30 in the morning and I find myself undergoing a familiar scene. I'm kicking the GBL habit, again. I first discovered the stuff through a friend, and it was truly miraculous. It was the kind of drug that made me want to stand up and cheer. It could get me through any situation, no matter how unpleasant.
'Existence In A Giant, Semi-Noncorporeal Pillow' a.k.a. 'WTF you actually have some free GBL just laying around randomly?! You rule.' It was just another rave night in early '07. It was simply one of those nights where I basically have just shit run out things to do.
When I first started taking GBL I thought it was a completely harmless health supplement/healthy alcohol replacement. Before taking GBL I had little experience with other drugs except cannabis which I used to smoke daily and very heavily until I changed countries and lost my suppliers.
I am female, aged 20, and I have used GBL at doses up to (and sometimes exceeding) 20ml a day, almost every day, for the past 2 years. However, I first tried it when I was 15. This report constitutes an effort to summarize my experiences. However, it should be noted that it cannot possibly be complete.
It all started when I was out at an event with my friends. Id heard of GBL (GHB) and that theyd tried it, and it was good, but I was reluctant to try it myself. This particular day, although very apprehensive, I did try it and once I knew what I was looking for I really enjoyed the experience.
Bluelight 8 threads 2 positive 3 neutral 3 cautionary visit
Dose – 1.8ml approx Preface I’ve been a big fan of GBL for some time now. Its easy to acquire, legal (in the UK anyway), easy to dose if you know how much your gelcaps can hold and easy to administer. My first time was back in November when I had 1.5ml and loved it, but I didn’t purchase some until February.
"Existence In A Giant, Semi-Noncorporeal Pillow" a.k.a. "WTF you actually have some free GBL just laying around randomly?! You rule." It was just another rave night in early '07. It was simply one of those nights where you basically have just shit run out things to do.
GBL – Inexperienced 1st time – Sober and Solvent! Weight: 65-70kg Substances consumed: None GBL Experience: 1st Time GBL 99.9% pure: I have my doubts based on dosage below. Background: Well after the usual research … I eventually got a few doses of GBL.
Background : Not your typical GBL user, I guess. I have only drank two alcoholic beverages in my life. The last time was 8 years ago. Also not using any other drugs (or medicines for that matter). I don't like alcohol, mainly due to it's toxicity and common effects (recklessness, aggression).
Weight : 176lbs Drug : GBL erowid Dose : 2ml @ 99.98% pure (est. 3.2g GHB) T + 0min Dose 2ml GBL in about 15ml Irn-Bru. The product itself smells like nail varnish and tastes like liquorish. T + 15min Wow, This stuff is great! My head feels kind of heavy, my reactions are slow but I feel so happy and relaxed.
I weigh 130lbs. Adult male. I received 100ml of GBL last week. In a way, I wish it didn't come. First, I measured out 1ml (1cc) in an insulin syringe. I have read the dose range is 1.5-2.5ml. I put it in apple cider. It has a chemical taste, not pleasent.
Took 1.5ml at 7.30 By 7.50 I was feeling the effects, music sounded better, felt really good and scoiable. 8.00 I had a rush over my body that felt like I was having an orgasm for about 2-5mins. Then I just felt like I was drunk but completely in control.
Sex: male Weight: 11 st (70kg) Dosage: roughly 1.5ml per hour for 3 hours plus roughly 0.5ml just under an hour later result: fell asleep in pub toilet for half an hour.
Bluelight Reference Guide
GHB / 1,4-B / GBL Discussion and Use
Bluelight’s primary GHB / 1,4-B / GBL discussion thread. GBL converts to GHB in the body; same dosing/withdrawal/recovery-position considerations apply.
Read full thread on Bluelight →
GBL's nerd page
Pharmacology, chemical data, effect profiles, and more
→
Helpful Links
Import into PsychonautWiki Journal
The PsychonautWiki Journal app includes GBL, but its built-in data can be thinner than ours. Importing this file adds a separate "GBL (Substance Search)" custom substance with our dose ranges and durations, so you can log against whichever you prefer. It leaves tolerance out on purpose, for the reason given under Tolerance above.
⬇ Download import file
Import this file as custom substances
and you get "GBL (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 GBL? Let us know. Reports are reviewed by moderators — this is not posted publicly.