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Dosage & Duration
Dosage
Doses are population estimates that vary widely between individuals.
Threshold~15 mg
Light15-20 mg
Moderate20-40 mg
Strong40-70 mg
Heavy70+ mg
Duration
Onset4-6 hours
After Effects1-10 hours
Subjective Effects
Subjective Effects not written up yet
Pharmacology
Pharmacology not written up yet
Interactions
Interactions not written up yet
An unlisted combination is an unknown one, not a safe one. Check a dedicated combination chart before mixing.
Tolerance
Tolerance not written up yet
Harm Potential
Addiction & Dependence
Psychological
LowAddiction and dependence risk appears low or negligible, although abuse is listed among serious adverse concerns and use is contraindicated in people with a history of drug abuse.
Physical
Extremely LowTolerance usually occurs, but dependence and addiction risks are considered negligible.
Toxicity
cardiovascular
Reported effects include tachycardia, arrhythmia, hypertension, hypotension, circulatory collapse, palpitations, and precordial pain; rare serious reports include cardiac arrest, cardiac failure, myocardial infarction, angina, and stroke.
central nervous system and psychiatric
Overdose may include confusion, assaultiveness, hallucinations, panic, restlessness, tremor, insomnia, irritability, hyperactivity, personality changes, and rare psychotic episodes.
gastrointestinal
Acute overdose may cause nausea, vomiting, diarrhea, and abdominal cramps.
Psychosis Risk
Chronic overdosage may develop into schizophrenia-like psychosis, and rare psychotic episodes and hallucinations are reported.
History & Culture
History & Culture not written up yet
Legality
International
Phentermine has approved, illicit, and investigational regulatory groupings.
By Country
Illegal1
United StatesIllegalPhentermine is listed by exact name as a Schedule IV stimulant at 21 C.F.R. § 1308.14(f)(9), effective July 6, 1973. The listing covers any quantity of phentermine, including its salts, isomers, and salts of isomers, unless specifically excepted or listed in another schedule. Federal law prohibits unauthorized possession, manufacture, distribution, dispensing, and possession with intent to manufacture, distribute, or dispense; possession obtained directly or under a valid prescription or practitioner order, and other authorized possession, is permitted. A current phentermine hydrochloride tablet is a Schedule IV prescription drug approved for short-term use as an adjunct in a weight-reduction regimen for specified patients with exogenous obesity.
References
Citations
- 21 C.F.R. § 1308.14 — Schedule IV. ecfr.gov (n.d.). https://www.ecfr.gov/api/renderer/v1/content/enhanced/current/title-21?part=1308§ion=1308.141
- Diethylpropion and Phentermine; Temporary Placement in Schedule IV; Interim Regulations, 38 Fed. Reg. 18013–18015. govinfo.gov (n.d.). https://www.govinfo.gov/content/pkg/FR-1973-07-06/pdf/FR-1973-07-06.pdf1
- 21 U.S.C. § 844 — Penalties for simple possession. uscode.house.gov (n.d.). https://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title21-section844&num=0&edition=prelim1
- 21 U.S.C. § 841 — Prohibited acts A. uscode.house.gov (n.d.). https://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title21-section841&num=0&edition=prelim1
- DailyMed — Phentermine hydrochloride tablet. dailymed.nlm.nih.gov (n.d.). https://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=0e893b62-bb07-4984-9f0a-3601435fbc27&version=141
- openFDA Drugs@FDA record — Phentermine hydrochloride (ANDA040526). api.fda.gov (n.d.). https://api.fda.gov/drug/drugsfda.json?search=application_number%3A%22ANDA040526%221
Article Status
Step 1 · Automated synthesisAn autonomous workflow built by Josie Kins compiled this article's foundation from information published across the web.
- Step 2 · First-pass reviewPending
Not yet reviewed — this article is pending editorial review by Lyrea.
- Step 3 · Citation reviewPending
No one has reviewed this article's citations yet. That second pass checks each claim against the source it cites.
Recent changes7 human edits · latest
Times are UTCNewest first
24 January 2026
Josie Kins · Updated the article · also 1,4-Butanediol, 1B-LSD, 1cP-AL-LAD and 573 more
Josie Kins · Updated the article · also 1,4-Butanediol, 1B-LSD, 1cP-AL-LAD and 573 more
Josie Kins · Updated the article · also 1,4-Butanediol, 1B-LSD, 1cP-AL-LAD and 573 more
Josie Kins · Updated the article · also 1,4-Butanediol, 1B-LSD, 1cP-AL-LAD and 573 more
Josie Kins · Updated the article · also 1,4-Butanediol, 1B-LSD, 1cP-AL-LAD and 573 more
Josie Kins · Updated the article · also 1,4-Butanediol, 1B-LSD, 1cP-AL-LAD and 573 more
Josie Kins · Updated the article · also 1,4-Butanediol, 1B-LSD, 1cP-AL-LAD and 573 more
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