Phenibut exposures and clinical effects reported to a regional poison center.
About a quarter of the people in this poison-centre series were taking phenibut for anxiety and one in five needed a breathing tube — what proven anxiety treatment could I use instead?
Weak or heavily disputed. Treat as a question, not an answer. how we score evidence
Caveat on this rating: A single-state case series of 56 calls, with coingestants documented in 36% of patients, cannot separate phenibut's effects from other drugs and cannot estimate how common these outcomes are among people who use phenibut. It scores low on the evidence rubric by design — it is a description of hospital cases, not a study of whether phenibut helps or harms.
Phenibut has never been approved by the FDA for any medical use in the United States and is not a lawful dietary supplement ingredient: the FDA has stated that phenibut does not meet the statutory definition of a dietary ingredient, that products listing it as one are misbranded, and it issued
The Minnesota Poison Control System logged 56 phenibut exposure calls over 19 years, but 48 of them (85.7%) came in the last five years of that span. Over half of patients had central nervous system effects and 11 (19.6%) required intubation for respiratory failure; 23% said they were using phenibut to treat anxiety and 48% were classified as abuse. No deaths occurred in this series.
Worth asking
About a quarter of the people in this poison-centre series were taking phenibut for anxiety and one in five needed a breathing tube — what proven anxiety treatment could I use instead?
Source
Phenibut exposures and clinical effects reported to a regional poison center. — McCabe DJ, Bangh SA, Arens AM, Cole JB. (2019)
Reputable peer-reviewed journal
Read the source: https://doi.org/10.1016/j.ajem.2019.02.044
DOI: 10.1016/j.ajem.2019.02.044
How this was scored
- Study design
- Case series or case report
- Funding
- Funding not disclosed
- Published in
- Reputable peer-reviewed journal
- Sample size
- 56
- Preregistered
- No
- Conflicts disclosed
- No
- Independent of proponent
- Yes
- Retracted
- No
Read the full scoring rubric, including what it can't tell you.
Published August 19, 2026.
Questions
How strong is the evidence behind this?
Resolv rates this source "contested". Weak or heavily disputed. Treat as a question, not an answer. It scores 39 out of 100 on our published rubric. One caveat travels with that badge: A single-state case series of 56 calls, with coingestants documented in 36% of patients, cannot separate phenibut's effects from other drugs and cannot estimate how common these outcomes are among people who use phenibut. It scores low on the evidence rubric by design — it is a description of hospital cases, not a study of whether phenibut helps or harms. The score is calculated from recorded facts about the source — study design, funding, publication venue, sample size, preregistration — not typed in by an editor.
What is the source for this?
Phenibut exposures and clinical effects reported to a regional poison center. — McCabe DJ, Bangh SA, Arens AM, Cole JB. (2019). Published in: Reputable peer-reviewed journal. DOI: 10.1016/j.ajem.2019.02.044. The full source is linked on this page so you can read it yourself.
Who paid for this research, and does that matter?
Study design: Case series or case report. Funding: Funding not disclosed. The researchers were independent of whoever benefits from the result. Industry sponsorship is one of the most reliably measured biases in medicine, which is why funding carries real weight in the score rather than sitting in a footnote.
Is phenibut, noofen, anvifen, fenibut, beta-phenyl-gaba, 4-amino-3-phenylbutyric acid, phenygam FDA approved for this use?
No. Its current status is: Not FDA-evaluated for this use. Phenibut has never been approved by the FDA for any medical use in the United States and is not a lawful dietary supplement ingredient: the FDA has stated that phenibut does not meet the statutory definition of a dietary ingredient, that products listing it as one are misbranded, and it issued
Is this medical advice?
This is information to bring to your prescriber, not medical advice and not a reason to change anything on your own. Nothing here is an instruction to stop or reduce a medication. If you are in crisis, call or text 988.
This is information to bring to your prescriber, not medical advice and not a reason to change anything on your own. Nothing here is an instruction to stop or reduce a medication. If you are in crisis, call or text 988.