Insomnia has plagued me my entire life. It started when I was 13. Puberty kicked in, and one night I just stopped sleeping. Throughout high school I tried many remedies: magnesium, melatonin, chloral hydrate, alcohol, Sonata, Ativan, Xanax, and Ambien. None really gave me extended relief.
Pentobarbital
Well-documented
Well-documented
Multiple authoritative sources agree on dosing and effects.
- 3 corroborating sources
- 1 ROA with full dose ladder
- duration data present
- 17 combo interactions documented
- toxicity data (PsychonautWiki, PubChem)
Well-documented
Multiple authoritative sources agree on dosing and effects.
- 3 corroborating sources
- 1 ROA with full dose ladder
- duration data present
- 17 combo interactions documented
- toxicity data (PsychonautWiki, PubChem)
Aliases: Nembutal, Novopentobarb, Pentobarbitone, Yellow jackets
Summary
Pentobarbital is a Schedule II controlled substance in the United States and similarly restricted internationally. It has largely been replaced by benzodiazepines for medical use due to its narrow therapeutic window and high addiction potential. The drug is currently used primarily in veterinary medicine for euthanasia and in some jurisdictions for physician-assisted suicide.
Dose Information
| ROA | Light | Common | Strong | Heavy |
|---|---|---|---|---|
| Oral | 50-100mg | 100-200mg | 200-300mg | 300mg+ |
| Intramuscular | 100-150mg | 150-200mg | - | 200mg+ |
| Intravenous | 50-60mg | 60-100mg | - | 100mg+ |
Light
Common
Strong
Heavy
Sources
Oral
Dose ladder — PsychonautWikiOnset, Duration & After-effects
| ROA | Onset | Comeup | Peak | Offset | Total |
|---|---|---|---|---|---|
| Oral | 15-60 min | 30-60 min | 1-3 hrs | 1-2 hrs | 2.75-7 hrs |
| Intramuscular | 10-25 min | - | 3-4 hrs | - | - |
| Intravenous | 1 min | - | 15-20 hrs | - | - |
Tolerance
Build-up
develops over 1–4 weeks of daily use; hypnotic tolerance faster than anxiolytic tolerance
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 barbiturates, you get used to the effects much more than to a dangerous dose, so the gap between a dose that works and one that kills shrinks the more you use. Stopping suddenly after regular use can cause convulsions and delirium.
Sources: FRANK: benzodiazepines · Alcohol and Drug Foundation: GHB · FDA 2020: benzodiazepine boxed warning · FDA 2019: gabapentinoids and breathing · NHS: alcohol use disorder · Phenobarbital label: drug abuse and dependence
Effects
Effect glossary — · full glossary
Positive
Negative
Positive
Negative
Positive
Negative
Combinations
Cross-Check Pentobarbital 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 2 reports 2 cautionary visit
I first started using pentobarb from a veterinary source recreationally and kept a back up supply for suicide if the worst came to the worst (I was in the throes of severe depression).
Pentobarbital's nerd page
Pharmacology, chemical data, effect profiles, and more
→
Helpful Links
Add missing routes to PsychonautWiki Journal
The PsychonautWiki Journal app already has Pentobarbital, but its built-in entry only covers Oral. Here are the other routes we have data for. You can't edit a built-in substance, but you can add a Custom Unit for any of these routes to log it.
⬇ Download import file
Import this file as custom substances
and you get "Pentobarbital (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. The manual values below work for older
versions.
Custom Unit doses
- Intramuscularcommon ~ 175 mg
- Intravenouscommon ~ 80 mg
Dose & duration (reference)
Pentobarbital: routes the PsychonautWiki Journal app is missing Source: SubstanceSearch (substancesearch.com) Intramuscular dose (mg): light 100-150 · common 150-200 · heavy 200+ Intravenous dose (mg): light 50-60 · common 60-100 · heavy 100+ Intramuscular duration: onset 10-25m · peak 3-4h · after-effects 1-36h Intravenous duration: onset 1m · peak 15-20h · after-effects 1-36h Note: ranges are harm-reduction guidance, not a prescription. Start low, go slow, and test your substances.
Custom Units carry a single dose per route, so the full ranges live in the reference above. A route's suggested dose is the midpoint of its common range. 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 Pentobarbital? Let us know. Reports are reviewed by moderators — this is not posted publicly.