Which anabolic steroids need an aromatase inhibitor?

Only the ones that aromatize to estrogen – primarily testosterone and, heavily, dianabol. DHT-derived compounds (masteron, primobolan, anavar, winstrol, proviron) and 19-nors (trenbolone) do not aromatize, so an aromatase inhibitor is generally not relevant for them; any estrogen management on a stack is about the aromatizing compound. Over-suppressing estrogen has its own harms, so an AI is a clinical decision, not automatic.

Anabolic steroids: honest compound profiles

Q: What determines how an anabolic steroid behaves?

Most of a compound's behaviour is predictable from a few structural facts: its base family (testosterone, DHT-derived, or 19-nor), whether it aromatizes to estrogen, whether it is 17-alpha-alkylated (oral and liver-straining), whether it is a 19-nor (progestin activity), its ester (which sets half-life and injection frequency), and how strongly it suppresses natural testosterone. Each of those maps to a specific side-effect it can cause and a specific way people manage it – which is exactly what the per-compound pages lay out.

Q: Are all oral steroids liver-toxic?

The 17-alpha-alkylated orals (dianabol, anadrol, winstrol, superdrol, halotestin, anavar, turinabol) are hepatotoxic because the alkylation lets them survive the liver's first pass – which is why users limit their duration, avoid stacking hepatic loads including alcohol, and monitor liver markers. Injectable compounds that are not 17-alpha-alkylated do not carry this specific oral liver toxicity, though they have other risks.

Q: Do anabolic steroids suppress natural testosterone?

Yes – essentially all of them suppress the hypothalamic-pituitary-gonadal axis to some degree, most of them strongly or totally. That is why a recovery plan (post-cycle therapy) and post-cycle bloodwork matter, and why the come-down after a cycle can be rough. The timing of any restart runs off the slowest-clearing ester in the stack.

A harm-reduction reference to the common anabolic-androgenic steroids. Most of what a compound does is predictable from a handful of structural facts – this hub explains how to read a profile, then links a per-compound page for each, and points at the bloodwork that catches problems early. It is educational, not medical advice, and not encouragement to use controlled substances.

By OptiPin Editorial·Last updated July 2026

Controlled substances · serious risks

Anabolic-androgenic steroids are Schedule III controlled substances in the US (prescription-only) and carry real, sometimes irreversible risks – cardiovascular strain and adverse lipids, natural-testosterone suppression and fertility impact, and (for oral 17α-alkylated compounds) liver toxicity. They are on the WADA prohibited list. This content exists so people who use anyway can understand mechanism and risk and monitor themselves; it is not a recommendation, and use should be clinician-supervised with serial bloodwork.

How to read a compound profile

Every per-compound page below leads with the same profile, because these six facts predict most of the behaviour and side-effect management:

• Base family – testosterone-based, DHT-derived, or 19-nor. Sets the overall character.
• Aromatization – does it convert to estrogen? If yes (testosterone, dianabol), estrogen-side management (water retention, gyno) comes into play; if no (most DHT-derived and 19-nors), it doesn't drive those.
• 17α-alkylated (oral) – methylation lets a compound survive the liver's first pass so it works orally, at the cost of liver strain. Orals are time-limited and liver markers get watched.
• 19-nor – nandrolone and trenbolone act on the progesterone receptor, adding prolactin-type side effects that non-19-nors don't have.
• Ester & half-life – sets injection frequency and, crucially, how long a compound lingers after a cycle (post-cycle timing runs off the slowest ester).
• Suppression – how hard it shuts down natural testosterone, which drives the recovery/PCT plan.

Read against those, a compound stops being a name on a forum and becomes a known quantity. The cycle-structure guide covers how these fit into phases, and the bloodwork guide covers the labs.

Compound references

Honest, harm-reduction profiles for each – family, aromatization, oral/liver status, suppression, reported dosing, side effects, and the labs that catch them:

All compounds: Anadrol · Anavar · Nandrolone (Deca) · Dianabol · DHB · Equipoise · Halotestin · Masteron · Primobolan · Proviron · Superdrol · Trenbolone · Turinabol · Winstrol

Testosterone itself and its esters are covered in the TRT pillar and the testosterone cypionate tracker; this hub focuses on the non-testosterone anabolics run in cycles.

Run the numbers

Three calculators cover the arithmetic a cycle needs. None of them tells you a dose is safe, because none of them can:

Steroid cycle calculator – weekly milligrams across a stack, the hormone actually delivered once ester weight is removed, per-injection doses and time to plateau, plus a load curve for every compound in the stack.

PCT calculator – when each compound in a cycle clears, which ester governs the wait and the earliest sensible start date counted from your last injection.

Steroid ester calculator – 250 mg of enanthate is not 250 mg of testosterone. Active hormone per dose, plus the equivalent dose in every other ester of the same hormone.

The three things that carry a cycle

Whatever the compound, the same discipline applies, and it's the reason OptiPin exists: track what you can't reconstruct later (compounds, doses, dates), put bloodwork on the same timeline (baseline, mid-run, end, and a recovery panel – lipids, hematocrit, liver markers, and the hormone picture), and tag the phases so an off-week reads as an off-week, not a compound failing. The cycle-structure guide and restart/PCT guide go deeper.

Track a cycle properly

Compounds, doses, phases & labs on one timeline

Multi-compound tracking, cycle-phase tagging, estimated clearance from each ester, and a phase-aware bloodwork checklist – private, on-device.

Download on the App Store

FAQ

What determines how an anabolic steroid behaves?

A few structural facts: base family (testosterone / DHT-derived / 19-nor), whether it aromatizes to estrogen, whether it's 17α-alkylated (oral, liver-straining), whether it's a 19-nor (progestin activity), its ester (half-life / injection frequency), and how strongly it suppresses natural testosterone. Each maps to a specific side effect and a specific management step – which is what the per-compound pages lay out.

Which steroids need an aromatase inhibitor?

Only aromatizing ones – mainly testosterone and (heavily) dianabol. DHT-derived compounds (masteron, primobolan, anavar, winstrol, proviron) and 19-nors (trenbolone) don't aromatize, so an AI isn't relevant for them; estrogen management on a stack is about the aromatizing compound. Over-suppressing estrogen has its own harms, so an AI is a clinical decision.

Are all oral steroids liver-toxic?

The 17α-alkylated orals (dianabol, anadrol, winstrol, superdrol, halotestin, anavar, turinabol) are hepatotoxic – the alkylation lets them survive the liver's first pass. Users limit duration, avoid stacking hepatic loads (including alcohol), and monitor liver markers. Non-alkylated injectables don't carry this specific oral toxicity, though they have other risks.

Do anabolic steroids suppress natural testosterone?

Yes – essentially all suppress the HPTA, most strongly or totally. That's why a recovery plan (PCT) and post-cycle bloodwork matter, and why the come-down can be rough. Restart timing runs off the slowest-clearing ester in the stack. See the restart guide.

Educational only, not medical advice. Anabolic-androgenic steroids are controlled substances with real health risks. OptiPin is a tracking tool and does not provide dosing or treatment advice, nor encourage use. Discuss any compound with a qualified clinician and understand your local law.

Cycle structure & tracking · PCT / restart · Bloodwork to monitor · High hematocrit · Clenbuterol & the ECA stack · TRT pillar · Tracking a multi-compound protocol · Peptides