VITAMINS & SUPPLEMENTS · GUIDE
Phenibut, Tianeptine and Kratom: FDA Warnings and Withdrawal Risks
What phenibut, tianeptine and kratom are, what the FDA and US poison-center data say, and why withdrawal and dependence need medical help. Information only; not a use guide.
Content last updated . This page has not been medically reviewed.
Back to NootropicsUrgent first
If someone is very drowsy, hard to wake, has trouble breathing, has a seizure, or may have taken too much of any of these, call 911 (US). For poisoning questions in the US, Poison Help is 1-800-222-1222; other countries are on Poison Help by country. If you are in emotional distress or thinking of harming yourself, call or text 988 (US). [1]Withdrawal from these substances can be serious. The published cases were managed in hospitals with several medicines, so see a clinician rather than going through it alone. [2]
What this page covers
These three substances are sold online, sometimes as "focus," "mood" or "relaxation" products. They are not safe focus supplements, and this page does not describe ways to use them. They are covered because people search for them next to nootropics. Related pages: dependence and withdrawal with stimulant and GABA-acting supplements and nootropic safety and claim checks.Evidence labels used here: evidence of harm (reports of serious effects), insufficient evidence (not enough trials to judge benefit), marketing claim.
At a glance
| Substance | What it is | US FDA position (as read) | Documented risks |
|---|---|---|---|
| Phenibut | A substance also known as phenyl-GABA, advertised online for anxiety, relaxation and sleep [3][4] | Does not meet the statutory definition of a dietary ingredient; supplements declaring it are misbranded (FDA page, 2023) [3] | Sedation, breathing depression, withdrawal with anxiety and psychosis [4][2] |
| Tianeptine | A prescription antidepressant in some European, Asian and Latin American countries [5] | Not approved as a drug in the US; not a dietary ingredient and an unsafe food additive (FDA page, 2023) [5] | Opioid-receptor activity, dependence, withdrawal, hospital admission [6][7] |
| Kratom | Leaves of a Southeast Asian tree sold as powders, capsules and extracts [8][9] | Not lawfully marketed as a drug, dietary supplement or food additive (FDA page, 2025) [8] | Liver toxicity, seizures, substance use disorder, withdrawal [8] |
Phenibut
Poison centers received 1,320 phenibut exposure calls between 2009 and 2019 in the US. [4] The CDC report says use and misuse can result in sedation, respiratory depression and reduced levels of consciousness, and that major effects occurred in one in eight reported exposures, with three deaths reported. [4] It also notes phenibut is not detected on routine urine drug screens. [4]A systematic review of 62 published cases found that most people obtained phenibut online. [2] In withdrawal cases the most common symptoms were anxiety, irritability or agitation, insomnia and psychosis. [2] In toxicity cases, 48.7% needed intubation. [2] These are case reports, so they show serious harm can happen, not how often. The review authors said the seriousness of the presentations reflects the potential dangers of phenibut. [2]
The CDC report says phenibut is uncontrolled and legal to possess in the US, even though the FDA position is that it cannot be listed as a supplement ingredient. [4]
Tianeptine
Tianeptine acts on opioid receptors. [6] An FDA page warns that consumers may inadvertently become addicted and should avoid all products containing it, especially those claiming to treat opioid use disorder. [5] The FDA says anyone with opioid use disorder should consult a healthcare provider. [5]A study of US poison center data (2015 to 2023) counted 892 single-substance tianeptine exposures. [7] About 40% needed hospital admission, including 22.9% to intensive care, and withdrawal accounted for 22.5% of exposures. [7] A published case report described a newborn with severe opioid-type withdrawal after the mother's prenatal use of a tianeptine supplement. [10] Whether tianeptine helps any thinking or focus outcome in healthy people: Proper evidence not found in the sources we read (we looked at FDA, CDC and PubMed records for tianeptine).
Kratom
The FDA says kratom is not appropriate for use as a dietary supplement. [8] It has warned consumers not to use kratom because of liver toxicity, seizures and substance use disorder. [8] Cases of dependence with tolerance and withdrawal have been seen, and newborns have shown withdrawal signs after prolonged exposure before birth. [8] Certain kratom products were contaminated with Salmonella or heavy metals. [8] NIDA adds that rare but serious effects have been reported and that much remains unknown. [9] For more, see Kratom: what it is, regulation and risks.Who is most at risk
Pregnant and breastfeeding people, children (poison centers report unintentional exposures in young children [4]), people who take sedatives, opioids or alcohol, and people with liver or kidney disease should treat any of these products as high risk. We found no source giving a safe level for any of them. Ask a clinician or pharmacist about medicine interactions: medication interactions.What to do instead
Report side effects through your clinician or the FDA MedWatch program. [8] For focus, sleep or mood concerns, see a clinician; Focus & Memory lists everyday starting points.Frequently asked questions
Is phenibut legal?
In the US it is legal to possess according to a 2020 CDC report, but the FDA says it is not a lawful dietary ingredient. [4][3] Other countries are not described in the sources we read.
Is kratom an FDA-approved supplement?
No. The FDA says there are no kratom drug products legally on the market and that kratom is not lawfully marketed as a dietary supplement. [8]
Can tianeptine be used to treat opioid addiction?
The FDA says people with opioid use disorder should consult a healthcare provider and avoid products with tianeptine. [5]
Are these withdrawal symptoms dangerous?
Published phenibut cases describe anxiety, agitation, insomnia and psychosis, often treated in hospital. [2] Tianeptine and kratom withdrawal are also reported. [7][8] See a clinician.
Do any of them improve memory or focus?
Proper evidence not found in the sources we read for phenibut or tianeptine. The FDA notes few well-designed human studies exist for kratom. [8]
References
- National Institute of Mental Health (US), "Find Help". Read 2026-10-23.
- Weleff J et al., "Clinical Presentations and Treatment of Phenibut Toxicity and Withdrawal: A Systematic Literature Review," J Addict Med 2023. Read 2026-10-23.
- FDA, "Phenibut in Dietary Supplements" (US, content current as of 07/12/2023). Read 2026-10-23.
- Graves JM et al., "Notes from the Field: Phenibut Exposures Reported to Poison Centers, United States, 2009-2019," MMWR 2020. Read 2026-10-23.
- FDA, "Tianeptine in Dietary Supplements" (US, content current as of 02/22/2023). Read 2026-10-23.
- El Zahran T et al., "Characteristics of Tianeptine Exposures Reported to the National Poison Data System, United States, 2000-2017," MMWR 2018. Read 2026-10-23.
- Quadir M et al., "Tianeptine Exposures Reported to United States Poison Centers, 2015-2023," J Med Toxicol 2025. Read 2026-10-23.
- FDA, "FDA and Kratom" (US Food and Drug Administration, content current as of 12/02/2025). Read 2026-10-23.
- National Institute on Drug Abuse (NIDA, US), "Kratom". Read 2026-10-23.
- Ikeri K et al., "Neonatal Opioid Withdrawal Syndrome Following Prenatal Use of Supplements Containing Tianeptine," Pediatrics 2024 (case report). Read 2026-10-23.