1-Andro

1-Andro (1-androsterone) is a non-methylated oral prohormone that converts in vivo to 1-testosterone — the same active molecule as injectable dihydroboldenone (DHB). It does not act on the androgen receptor meaningfully in its parent form; its effects are entirely downstream of hepatic conversion. Understanding the two-step metabolism, the unique A-ring chemistry, and the reason it still hammers lipids despite lacking 17α-alkylation is the key to running it intelligently.

Two-Step Hepatic Conversion to 1-Testosterone#

Ingested 1-androsterone undergoes sequential enzymatic conversion in the liver: 1-androsterone → 1-androstenediol (via 17β-HSD) → 1-androstenedione → 1-testosterone (via 3β-HSD). The final product, 1-testosterone (17β-hydroxy-5α-androst-1-en-3-one), is the active androgen responsible for every outcome users experience — lean mass, strength, hardness, suppression, and lipid damage.

"Oral 1-androsterone is subject to rapid conversion by hepatic enzymes, resulting in the detection of 1-testosterone and 1-androstenedione metabolites in urine samples from athletes after supplementation." — Parr MK et al., Steroids, 2011

Practically: the parent compound is a delivery vehicle, and first-pass glucuronidation is aggressive. This is why effective doses sit in the 300–500 mg/day range — you need to overwhelm conjugation to get meaningful serum 1-testosterone — and why dosing is split 2–3× daily to keep metabolite levels flat across the day.

Androgen Receptor Agonism Without Aromatization#

1-Testosterone is a full AR agonist with an anabolic:androgenic ratio of roughly 200:100 in classical Hershberger assays — stronger mg-for-mg at the receptor than testosterone itself. The Δ1 double bond in the A-ring is the critical structural feature: it blocks aromatase from acting on the molecule, so no estrogen conversion occurs. There is no need for an AI on cycle, and gyno is not a risk vector from 1-Andro itself.

For the user, this is a double-edged sword. The dry, hard, vascular look that 1-Andro is famous for comes from the absence of estrogenic water retention. The flat joints, reduced libido, and occasionally irritable mood come from the same place — estrogen does real work for joint lubrication, sexual function, and wellbeing, and running 1-Andro solo starves you of it. This is the mechanistic rationale for the 1-Andro + 4-Andro stack: 4-Andro converts to testosterone (which aromatizes normally), restoring a baseline of estrogen to cushion the dry 1-test signal.

Non-5α-Reducible A-Ring#

Because 1-testosterone is already 5α-reduced, it is not a substrate for 5α-reductase. It cannot be converted into DHT in scalp, prostate, or sebaceous tissue. On paper this should make 1-Andro a hair-friendly androgen — and relative to a pure test base, it is somewhat kinder.

In practice, the AR itself is still expressed in hair follicles, and 1-testosterone binds AR strongly. Users genetically predisposed to androgenic alopecia still report shedding on 1-Andro cycles, just typically less aggressive than on a testosterone-only run of equivalent anabolic load. Finasteride and dutasteride will not protect you here — they block 5α-reductase, which 1-testosterone has already bypassed. Topical antiandrogens (RU58841, pyrilutamide) are the only mechanistically valid scalp defense on a 1-Andro cycle.

Nitrogen Retention and Lean Tissue Accrual#

Once 1-testosterone binds AR in skeletal muscle, the downstream cascade is classical: the ligand-receptor complex translocates to the nucleus, binds androgen response elements, and upregulates transcription of genes governing myofibrillar protein synthesis, satellite cell activation, and nitrogen retention. The Δ1-5α configuration appears to produce a particularly potent AR activation profile in muscle relative to accessory tissues, which is the mechanistic basis for the high anabolic rating.

This translates to measurable body composition changes in controlled conditions:

"Compared with the placebo, the 1-androsterone group demonstrated a significant increase in lean body mass (+6.3%)... accompanied by a significant reduction in fat mass (−24.6%) over the 4-week intervention." — Granados J et al., Journal of Strength and Conditioning Research, 2014

A 6.3% lean mass gain in 4 weeks at only 330 mg/day is substantial — comparable to low-dose injectable AAS — and is why 1-Andro remains the most legitimate oral prohormone still sold over the counter.

Hepatic and Lipid Impact Despite Non-Methylation#

1-Andro is not 17α-alkylated, which is the usual culprit for oral steroid liver toxicity. Yet the same 330 mg × 4-week trial saw AST more than double and HDL drop by nearly 40%:

"1-androsterone supplementation for 4 weeks resulted in marked reductions in HDL cholesterol (−38.7%) and increases in LDL cholesterol (+32.8%), as well as significant elevations in liver enzymes (AST +113.8%)." — Granados J et al., Journal of Strength and Conditioning Research, 2014

The mechanism here is androgen-load-driven rather than methylation-driven. High-dose oral androgen exposure suppresses hepatic lipase regulation and stresses hepatocytes regardless of the C17 position. This is why TUDCA, NAC, fish oil, and citrus bergamot are non-negotiable on cycle, why cycles cap at 6–8 weeks, and why bloodwork at baseline, mid-cycle, and 6 weeks post-PCT is the standard of care. You can run 1-Andro well — you just cannot run it casually.

Common (most users)#

• Lipid shift (HDL down, LDL up) — the most reliable side effect. Expect HDL to drop meaningfully within 2–3 weeks. Mitigate with citrus bergamot 1000 mg/day, fish oil 3–4 g/day, daily cardio, and keeping cycle length to 4–6 weeks. Lipids normalize 8–12 weeks post-PCT.

"1-androsterone supplementation for 4 weeks resulted in marked reductions in HDL cholesterol (−38.7%) and increases in LDL cholesterol (+32.8%), as well as significant elevations in liver enzymes (AST +113.8%)." — Granados et al., J Strength Cond Res (2014)

• Elevated liver enzymes — AST in particular can double even though 1-Andro is non-methylated. Run TUDCA 500 mg/day and NAC 1200 mg/day throughout. Do not stack with alcohol or other hepatotoxic compounds.
• Joint dryness / "flat" feeling — non-aromatizing androgens give no estrogen cushion. Mitigate by pairing with 4-Andro (adds mild aromatization) or keeping fish oil and collagen intake high.
• Back and shin pumps — classic dry-compound pump. Taurine 3–5 g/day and adequate sodium/electrolytes help significantly.
• Lethargy late in cycle — usually HPTA suppression showing up around week 4–5. Expected, resolves in PCT.
• Libido dip mid-cycle — natural test suppresses while 1-test doesn't offer much libido drive on its own. The canonical fix is running 4-Andro alongside.

"Running 1-Andro with 4-Andro is the classic pairing — the dry, hard muscle of 1-andro gets some balance from the 'wet' test conversion, and libido doesn't crash as hard." — r/prohormones community (2024)

Uncommon (dose-dependent or individual)#

• Blood pressure creep — more likely at 440+ mg/day or in users already borderline. Monitor BP at home twice weekly; add hawthorn, garlic extract, CoQ10. If systolic climbs above 140, drop dose or end the cycle.
• Hair shedding in predisposed users — 1-testosterone isn't a 5α-reductase substrate, but it's still an AR agonist in scalp tissue. If you're MPB-prone, have a topical antiandrogen strategy (RU58841, pyrilutamide) in place prior to initiating a cycle.
• Serum creatinine elevation / apparent GFR drop — partly real muscle-mass signal, partly androgen effect on kidney handling. Confirm with cystatin C if your creatinine-based eGFR looks alarming mid-cycle.
• Acne / oily skin — less common than with aromatizing compounds but reported. Topical adapalene handles it.
• Irritability and sleep disruption — dose-timing issue. Move the last dose earlier in the day.
• Gyno from a 1-Andro / 4-Andro stack — 4-Andro aromatizes. If nipples get itchy, add an AI at low dose (aromasin 6.25 mg EOD) — 1-Andro itself does not require one.

Rare but serious#

• Cholestatic liver injury — dark urine, pale stools, jaundice, RUQ pain, persistent itching. Stop immediately and get a CMP + GGT. More likely if stacked with a 17α-methylated oral (Superdrol, M1T) — which you shouldn't be doing.
• Severe lipid disruption in susceptible users — HDL into single digits, LDL >200. If mid-cycle bloodwork looks like this, end the cycle early rather than finishing the bottle.
• Cardiac strain / LVH with repeated long cycles — an AAS-class risk, not a 1-Andro-specific one, but running prohormone after prohormone with no washout compounds it. Respect time off.
• Persistent HPTA suppression past 8 weeks post-PCT — rare with a proper SERM protocol, but possible in users who ran long cycles, skipped PCT, or stacked multiple prohormones. Bloodwork at 6 weeks post-PCT; if total test is still suboptimal, extend PCT or consult.

Hard contraindications#

• Untreated hypertension or dyslipidemia — 1-Andro makes both dramatically worse within weeks. Get baseline under control first or pick a different compound.
• Existing hepatic impairment or elevated baseline LFTs — AST more than doubles in healthy subjects at 330 mg/day. Do not add this insult to an already stressed liver.
• Stacking with 17α-methylated orals (Superdrol, M1T, methylstenbolone) — compounding hepatotoxicity for no good reason. If you want a methyl, run it alone.
• Near-term plans to conceive — expect suppressed LH/FSH and degraded spermatogenesis for months post-cycle. Bank sperm first or wait.
• Female use — 1-testosterone exposure carries real, potentially irreversible virilization risk (voice deepening, clitoral hypertrophy, facial hair). This is not a women's compound.
• Under 21 — premature epiphyseal closure risk. Wait.

Gender and PCT considerations#

Women: not appropriate. There is no "low dose" of 1-Andro that is safe for female physique use — the androgenic load on a female endocrine system is disproportionate and the virilization signs (voice changes in particular) do not reverse.

Fertility: expect full HPTA suppression on any meaningful cycle. Spermatogenesis typically recovers within 3–6 months of a clean PCT, but if you're planning conception in the next 6–12 months, choose a different approach.

PCT is mandatory, not optional. The "it's just a prohormone" framing is how users end up with a 9-month recovery instead of a 4-week one. Standard protocol:

No AI is needed during PCT for a 1-Andro solo cycle — 1-testosterone doesn't aromatize. If you ran it with 4-Andro, keep a low-dose AI on hand in case of rebound estrogen. Bloodwork at 6 weeks post-PCT confirms recovery; most users see total test back in range by then with lipids normalizing shortly after.