Stanozolol

a 17-alpha-alkylated DHT-derived androgen used historically as an oral tablet and injectable aqueous suspension, with controlled human lipid harm and no validated human terminal half-life.

tier B · androgens · HDL -33% in a 6-week human crossover trial

verdict

stanozolol's strongest human evidence is a controlled demonstration of large adverse lipid changes, not a validated body-composition outcome or a human half-life.

if you are asking whether oral and injectable stanozolol are different molecules — no. the injection is an aqueous suspension of stanozolol, not an ester. the 17-alpha alkyl group remains, and no controlled route comparison establishes liver safety for injection.

if you are asking whether the human half-life is 9 hours — no primary human terminal-half-life study supporting that value was located. the WHO monograph calls elimination short without supplying that number.

if you are asking what the horse curve means — 82.1 hours is an animal-only apparent terminal half-life after 0.55 mg/kg intramuscular aqueous suspension in six horses. it does not apply to oral humans or define a human injection interval.

The page separates human oral biomarker evidence from horse intramuscular suspension PK and never assigns the animal value to oral stanozolol.

why B-tier

B tier reflects controlled human lipid and endocrine evidence plus clear historical product identity. No validated human half-life, modern body-composition endpoint, current approval, or contemporary long-term safety file exists.

the core tension

Stanozolol lacks a validated human half-life and modern body-composition outcome, yet it has one of the class's cleanest controlled human demonstrations of substantial lipid harm.

what it is

Stanozolol is a 5-alpha-reduced, pyrazole-fused, 17-alpha-methyl androgen. Historical Winstrol tablets were oral. Injectable products suspend unesterified stanozolol crystals in water rather than attaching a depot ester.

what it does

It activates the androgen receptor and strongly changes hepatic protein and lipid handling. In a controlled human crossover, oral stanozolol markedly increased hepatic lipase and worsened HDL, HDL2, apolipoprotein A-I, and LDL.

origin

Winstrol NDA 012885 was a historical US product. FDA withdrew approval effective August 20, 2010 at the sponsor's request because it was no longer marketed, not because FDA made a safety or effectiveness finding in that notice.

why researchers are interested

A non-aromatizing reputation and an injectable form are often treated as protective. Neither neutralizes 17-alpha-alkylation, lipid injury, endocrine suppression, or the absence of modern outcome and long-term safety trials.

does it work

Controlled human studies establish endocrine and lipid effects. The best isolated six-week crossover recorded similar body-weight gain to injectable testosterone but did not establish lean mass. The defensible headline is measured biomarker harm, not a clean muscle outcome.

claims vs the data

• injectable Winstrol avoids oral liver risk — contradicted — the injectable is the same 17-alpha-alkylated molecule in aqueous suspension, not an ester.
• stanozolol has a proven 9-hour human half-life — unsupported — no qualifying primary human terminal PK source was located.
• stanozolol is lipid-friendly — contradicted — the controlled crossover recorded large adverse HDL, HDL2, ApoA-I, LDL, and hepatic-lipase changes.

key facts

• molecular formula: C21H32N2O
• molecular weight: 328.50 g/mol
• amino acids: n/a (steroidal small molecule, not a peptide)
• half-life: no validated human terminal half-life; horse intramuscular suspension apparent terminal half-life 82.1 hours
• type: 17-alpha-methyl, 5-alpha-reduced pyrazole-fused anabolic-androgenic steroid; oral tablet or intramuscular aqueous suspension, not an ester
• CAS: 10418-03-8
• -33% HDL in controlled oral trial
• +29% LDL in the same trial
• 82.1 h horse IM suspension animal proxy
• 0 validated human half-life studies

frequently asked questions

Is injectable stanozolol an ester?

No. It is an aqueous suspension of unesterified stanozolol, so the 17-alpha-alkylated molecule remains. No controlled human route comparison establishes that injection is liver-safe or quantifies relative hepatic risk.

What is the human half-life?

No qualifying primary human terminal-half-life value was located. The commonly repeated 9-hour number is not published here.

Can the 82.1-hour horse value be used for oral stanozolol?

No. It belongs to intramuscular aqueous suspension in horses and is displayed only as animal-only formulation-specific PK.

Was Winstrol withdrawn for safety?

The 2010 Federal Register notice says the sponsor requested withdrawal because Winstrol was no longer marketed and states that the withdrawal was not a safety or effectiveness finding.

related peptides

• Oxandrolone — another non-aromatizing 17-alpha-alkylated oral with human outcome data
• Methandienone — another oral 17-alpha-alkylated androgen with an old performance trial
• testosterone — the injectable comparator in the lipid crossover

reptides grades the research record and cites the literature behind every call. research reference only; not medical advice.