Do I take tamoxifen at the start or the end of a cycle?
Both are possible, but the cleaner split is: for acute gyno mid-cycle, add it day by day until symptoms disappear; for PCT, start after the aromatising compound has fully cleared — roughly 14–18 days after the last enanthate shot, three to four days after propionate.
How do I know the PCT is working?
Subjective markers: morning wood coming back, mood steadying, testicles regaining their normal size. Objectively only bloods answer it — total testosterone, LH and FSH about four to six weeks after the last tamoxifen dose give you a reliable picture. A single low reading at the tail end of PCT is not rare and shouldn’t automatically push you into extending the run.
Can I stack tamoxifen with HCG?
Yes, and many protocols do it deliberately. HCG hits the Leydig cells directly (as an LH analog), tamoxifen hits the central system (releasing LH). The combined pattern — HCG in the last cycle weeks and/or the transition, tamoxifen through the actual PCT — has held up in real use. Controlled trials on this exact protocol don’t exist though.
Do I need to worry about my eyes?
For years-long oncology use, yes — cataracts and retinal changes are documented. For a four-to-six-week PCT the risk is low. Anyone noticing visual issues (double vision, colour distortion, flashes) should stop and get it checked medically.
What about endoxifen as an alternative?
Endoxifen is the active metabolite and is being studied as a direct drug in some clinical trials. It isn’t commercially available in a reliable form right now — not as a licensed medicine and not as a serious grey-market product. A CYP2D6 poor metaboliser who doesn’t respond well to tamoxifen usually switches to clomiphene, not endoxifen.
What is the price of Tamoxifen at the steroid shop LabGain?
Steroid shop LabGain offers a wide selection of Tamoxifen in stock.
Buy Tamoxifen at prices ranging from 35 EUR to 40 EUR.
What other steroids for bodybuilding besides Tamoxifen are available for sale?
We offer a great selection of Oral and Injectable steroids, PCT, Fat burners, HGH and SARMs. We're sure that you find the best solution for your needs.
Tamoxifen for lifters: SERM pharmacology, PCT protocols and the safety picture nobody advertises
Ask ten guys in a gym chat what “nolva” means and ten will say tamoxifen citrate. That’s the SERM ICI (now AstraZeneca) developed in 1961 as a fertility drug, watched fail as an ovulation inducer, then quietly rebuilt into a cornerstone of endocrine breast-cancer therapy. Five decades of clinical data. Dozens of landmark trials. A side-effect list oncology knows in fine detail.
That the same molecule ends up in bodybuilding forums as the go-to PCT tool and the acute-gyno brake isn’t coincidence. Receptor pharmacology in a man on exogenous testosterone doesn’t behave fundamentally differently than in a pre-menopausal patient with a hormone-sensitive tumour. What changes is the dose, the duration and the medical framing — the last of which the community usually skips.
Two jobs it does in the bodybuilding context
Post-cycle therapy
After you drop an aromatising cycle, the endogenous axis is asleep. The pituitary stops sending LH, the Leydig cells idle, testosterone reads well below the physiological floor. Tamoxifen breaks the negative feedback loop, LH rises — the testes get a signal again.
A pragmatic community protocol: 40 mg per day for the first two weeks, then 20 mg for another two to four weeks. Alternatively 20 mg flat across four to six weeks. When you start depends on the half-life of the longest ester in the cycle — for enanthate, typically 14 to 18 days after the last shot; for propionate, three to four days.
The rule people forget: PCT doesn’t work while exogenous testosterone is still being released from the depot. Start too early and you’re suppressing yourself.
Acute gynecomastia
Tender, growing breast tissue on cycle is the alarm bell. The classic Alvarez pattern — itches, burns, hurts to touch — usually gives two to four weeks before a palpable lump sets in. Once the fibrous transformation is established, surgery is often the only fix.
Before that point, tamoxifen can shift the picture: 20–40 mg per day until the symptoms fully clear. For catch-it-early irritation a few days is often enough. For a palpable nodule, several weeks. Adding anastrozole makes sense only if the systemic estradiol reading is measurably high — not as a default.
Dose overview
Purpose
Daily dose
Duration
Active gyno symptoms
20–40 mg
Until symptoms clear
Classic PCT
20 mg
4–6 weeks
Loading PCT alternative
40 mg → 20 mg
2 + 2 weeks
Terminal half-life of the parent: 5 to 7 days. Of endoxifen (the active metabolite): up to 14 days. That’s why one dose a day is enough — the time of day matters less than not skipping. Empty stomach, plenty of water.
What the molecule actually does
Chemistry: C26H29NO as the base, C26H29NO · C6H8O7 as the citrate salt, molecular weight 371.5 g/mol (base), CAS 10540-29-1. Pharmacology: a selective estrogen-receptor modulator. That “selective” is the whole point — tamoxifen is neither a clean agonist nor a clean antagonist. It behaves differently depending on the tissue.
The parent compound is a prodrug. The liver converts it via CYP2D6 into endoxifen, the actual active metabolite with 30- to 100-fold higher affinity for the estrogen receptor. Roughly 7% of Caucasians carry genetic variants (poor metabolisers) with reduced CYP2D6 activity — for them the effect is noticeably weaker, and serum endoxifen testing can quantify it.
Tissue-specific behaviour
Breast tissue. Antagonist here. Occupies the receptor without activating it. That’s why it works in both pre-menopausal breast cancer and acute cycle-related gynecomastia.
Pituitary. Also antagonist. Blocks the estradiol feedback on the gonadotropes, LH and FSH climb. In men the LH bump restimulates the Leydig cells and endogenous testosterone production comes back online — at the end of the day this is the reason SERMs matter in post-cycle work at all.
Bone and liver. Here tamoxifen behaves as an estrogen agonist. Cuts both ways: a wanted side effect (better lipid profile, HDL up) and an unwanted one (higher thrombosis risk through the liver-produced coagulation cascade).
Tamoxifen vs. clomiphene
Both SERMs. Both PCT-capable. The difference sits in the side-effect profile and the receptor binding.
Tamoxifen
Clomiphene
LH/FSH stimulation
Sufficient at 20 mg/day
25–50 mg/day typical
Effect on breast tissue
Stronger antagonist
Noticeably weaker
Characteristic side effects
IGF-1 suppression, thrombosis risk
Visual disturbances, mood swings
Tolerability on average
Better
More variable
Rule of thumb: for active or looming gyno, tamoxifen hits harder. For a plain axis restart with no breast issue, clomiphene often does the job. Stacking 20 mg tamoxifen with 25 mg clomiphene is also reported, but rarely necessary.
Where it gets unpleasant: side effects and the hard risks
Oncology sees tamoxifen with a very deep evidence base. Common but usually manageable:
Hot flushes, mostly in the first weeks
Nausea, headaches, fatigue
The infamous “brain fog” — reduced cognitive sharpness during use
A specific thing for lifters: IGF-1 suppression. Tamoxifen lowers systemic IGF-1 measurably, which can brake muscle building while you’re on it. Tolerable across a four-to-six-week PCT — an argument for keeping any sub-cycle gyno intervention as short as possible.
The hard risks sit in the boxed warning of the US label: elevated risk of venous thromboembolism, thromboembolic stroke and — in women with an intact uterus — endometrial carcinoma. For men, cardiovascular endpoints are the relevant piece. Pre-existing clotting tendency, smoking, obesity, combination with high-dose anabolics all push the risk up further.
One point the community keeps glossing over: tamoxifen is not the answer for progesterone- or prolactin-driven gynecomastia under 19-nor compounds like trenbolone or nandrolone. In that setting it can even upregulate progesterone receptors and make the situation worse. Cabergoline is the correct route there.
Legal status and testing
Tamoxifen is a prescription drug in the US (Rx), the UK (POM) and the EU. Legal supply runs only through a doctor and a pharmacy. Generic tablets are available from Teva, Mylan, Accord, Sandoz and others — at prices well below what grey-market vendors ask for the same tablet count.
In organised sport tamoxifen sits on the WADA Prohibited List, category S4.2 (Anti-estrogenic substances), banned at all times. WADA’s 2026 rationale: SERMs can modulate the hormonal environment, boost the effect of anabolic agents, or muddy their traces in the endocrine picture. The International Testing Agency has suspended several athletes in the past few years on positive tamoxifen findings — including the Kuwaiti ju-jitsu fighter with a multi-substance result (drostanolone, 19-NA, anastrozole, tamoxifen) and a Russian wrestler with a two-year ban.
Where the grey market goes wrong
The regulated pharmacy is the one route that reliably locks down origin, purity and dose. Everything below it — “UGL nolva”, “research-grade tamoxifen”, raw powders shipped from the Far East — is a bet on label claims that rarely get independently checked. The Polish 2019 customs analysis of 63 seized PCT products found that 34.9% contained none of the declared active ingredient and 6.4% carried extra undeclared substances. For a molecule whose whole PCT logic depends on LH stimulation and receptor saturation, unknown purity isn’t a rounding error — it’s a systemic problem.
What we carry: Magnus tamoxifen in the 100-tab pack at 10 mg — the same base formulation the PCT community defaults to — and Prime’s 50-tab pack at 10 mg for shorter runs. Other brands or pack sizes can be ordered on request; the lead time depends on the batch availability at the specific supplier.
