Post Cycle Therapy: Nolvadex vs Clomid — What Works Better
Skipping PCT after an AAS cycle is one of the most common mistakes. We compare Tamoxifen and Clomiphene protocols, timing after different esters, and how to restore natural testosterone production.
What Happens to Your Hormones on Cycle
Exogenous testosterone (and all anabolic steroids) suppresses the hypothalamic-pituitary-gonadal (HPG) axis via negative feedback. The hypothalamus detects elevated androgen/estrogen levels and stops releasing GnRH. The pituitary stops releasing LH and FSH. The testes receive no signal to produce testosterone and begin to atrophy. After a 10–12 week cycle, endogenous testosterone production can drop to near zero. PCT exists to restart this suppressed axis.
When to Start PCT
Timing is critical and depends on the ester used. Testosterone Enanthate (half-life 7–8 days): start PCT 14–16 days after last injection. Testosterone Propionate (half-life 2–3 days): start PCT 3–4 days after last injection. Short-ester cycles recover faster. Starting PCT too early while residual hormone levels are still high is counterproductive — the continued androgen signal will continue suppressing the axis. Use a half-life calculator: wait until blood levels drop below ~20 mg/week equivalent.
Nolvadex (Tamoxifen): Mechanism and Protocol
Tamoxifen is a Selective Estrogen Receptor Modulator (SERM). In the hypothalamus and pituitary, it blocks estrogen receptors, tricking the brain into thinking estrogen is low — which increases GnRH, LH, and FSH secretion. This directly stimulates the testes to resume testosterone production. Standard PCT protocol: 40 mg/day weeks 1–2, 20 mg/day weeks 3–4. Nolvadex simultaneously protects against gynecomastia during PCT when testosterone is rising unevenly.
Clomid (Clomiphene): Mechanism and Protocol
Clomiphene also blocks estrogen receptors centrally, but has a stronger LH-stimulating effect than Nolvadex. It also has a weaker estrogenic agonist component at some tissue sites. Standard protocol: 50 mg/day weeks 1–2, 25 mg/day weeks 3–4. Side effects: Clomid can cause visual disturbances (rare but concerning), mood swings, and emotional sensitivity due to its partial agonist activity. For this reason, many coaches prefer Nolvadex as first-line PCT.
Nolvadex vs Clomid: Head-to-Head
A study directly comparing both SERMs in hypogonadal men found both raised LH, FSH, and testosterone effectively. Clomid raised testosterone slightly higher but caused significantly more side effects. The combination (Nolvadex 20 mg + Clomid 25 mg daily) is popular for harsher or longer cycles — it provides a synergistic effect on the HPG axis. Avoid running either SERM for more than 6 weeks continuously, as prolonged SERM use can have paradoxical effects on the axis.
Supporting Supplements During PCT
Zinc: 30 mg/day — cofactor for testosterone synthesis and 5-alpha reductase. Vitamin D3: 3,000–5,000 IU/day — essential for Leydig cell testosterone production. Ashwagandha (KSM-66): 600 mg/day — reduces cortisol by 20–30%, which competes with testosterone for precursor molecules. HCG during cycle (500–1,000 IU twice weekly) prevents testicular atrophy and dramatically shortens PCT duration — worth considering for cycles longer than 10 weeks.
Written by
Ivan Kowalski
Exercise Physiologist