Issues With Using Tamoxifen (Nolvadex) for Bodybuilding and Why Enclomiphene Is the Smarter Modern PCT 2025

TAMOXIFEN (NOLVADEX) FOR BODYBUILDING SUMMARY

We get an almost daily question where customers ask us what we suggest for PCT after a prohormone cycle and how the person in question has been told by everybody they must use a prescription breast cancer drug called Tamoxifen (sometimes sold under the brand name Nolvadex), to ensure they retain their muscle gains and prevent potential problems with gynecomastia. For years, that was standard advice but it's now very outdated. While Tamoxifen can help prevent estrogen-related gyno, it also disrupts your body's hormonal balance in ways that actually undermine muscle retention, libido, and recovery. We will then compare tamoxifen to Enclomiphene to see why if you are using an SERM how it compares to tamoxifen.

What Does Tamoxifen Do?

Tamoxifen is a Selective Estrogen Receptor Modulator (SERM) - it blocks estrogen in the brain and breast tissue but mimics estrogen in other tissues, such as the liver. During a cycle, that brain-level antagonism can suppress estrogen too much, blunting libido and slowing muscle development - a reason why aromatising compounds tend to perform better is a little estrogen is beneficial to gaining muscle mass. Meanwhile, the liver's estrogenic response increases SHBG (binding your free testosterone) [1] and lowers IGF-1 [2], two changes that directly reduce strength and recovery. So, while Tamoxifen looks protective on paper, it often undoes part of the anabolic benefit of your cycle.

The 5 Mechanisms That Make Tamoxifen a Bad PCT Choice

1. It Raises SHBG and Lowers Free Testosterone

Tamoxifen behaves like estrogen in the liver, which increases Sex Hormone-Binding Globulin (SHBG). SHBG binds to testosterone and makes it inactive [3].
Result: Total testosterone may increase, but free testosterone, the active form responsible for strength, muscle growth, and libido - drops sharply.

2. It Suppresses IGF-1 and Slows Recovery

That same estrogenic activity in the liver suppresses Insulin-like Growth Factor-1 (IGF-1), a hormone critical for muscle repair and growth [2].
Impact: Recovery becomes slower, connective tissue weakens, and it becomes harder to maintain lean muscle mass after your cycle.

3. It Causes Estrogen Rebound and Post-PCT Gyno

A Journal of Endocrinology study showed that Tamoxifen increased testosterone by around 50% but estrogen by more than 340%, even at a low dose of 10 mg [3]. When you stop taking Tamoxifen, that elevated estrogen floods back into unblocked receptors.
Result: Rebound gynecomastia, softer appearance, reduced libido, and delayed hormonal recovery.

4. It Does Not Protect Against Progesterone-Driven Gyno

Tamoxifen only blocks estrogen receptors. It does nothing to control progesterone or prolactin, both of which can also trigger gynecomastia. If your cycle includes progestogenic compounds such as 19-nor derivatives, you'll need support that targets dopamine signalling. Dopamine inhibits prolactin release through D2 receptor activation, helping to offset progesterone-related side effects.

Supplements that enhance dopaminergic tone, such as L-Dopa (from Mucuna Pruriens), 9-MBC, or Bromantane, are ideal for this purpose.

• L-Dopa rapidly increases dopamine levels and helps suppress prolactin.
• 9-MBC supports long-term dopaminergic recovery and receptor sensitivity.
• Bromantane enhances dopamine synthesis and motivation while improving hormonal balance post-cycle.

These compounds can significantly reduce the risk of progesterone-driven gyno, mood crashes, and libido issues that Tamoxifen alone cannot address.

5. It Harms Mood, Energy, and Libido

When SHBG is high, free testosterone is low, IGF-1 is suppressed, and estrogen fluctuates unpredictably.
Result: Mood crashes, low energy, reduced libido, poor sleep, and lack of motivation — the exact opposite of what a proper PCT should deliver.

Tamoxifen's Hidden Health Risks

Risk	Summary
Carcinogenic Potential	Classified by the IARC as a Group 1 carcinogen after long-term therapeutic use [5].
Liver Damage	Associated with fatty liver disease and structural liver changes in multiple studies [7][8].
Cataracts and Vision Loss	Shown to cause ocular toxicity in both animal and human data [9][10].
Blood Clots (VTE)	Promotes clotting factors in the liver, increasing risk for athletes with high blood pressure or hematocrit.

 

Enclomiphene: The Modern PCT Solution

Enclomiphene is the purified, active isomer from Clomiphene that delivers everything Tamoxifen promises without the baggage [11]. It selectively boosts LH and FSH release to restart natural testosterone production, yet it doesn't elevate SHBG or crush IGF-1. We recommend you read our detailed guide on enclomipehene use vs other PCT options beyond just tamoxifen alone.

Key Advantages:

• Powerful stimulation of natural testosterone recovery [12]
• Preserves free testosterone instead of binding it [11]
• Minimal estrogen rebound or mood disruption [12]
• Cleaner safety profile with no liver, eye, or clotting toxicity [12]

 

Tamoxifen vs Enclomiphene: Head-to-Head

Feature	Tamoxifen (Nolvadex)	Enclomiphene
Free Testosterone	Decreases (via SHBG rise)	Preserves or increases
IGF-1 Levels	Suppressed	Maintained
Estrogen Rebound	High risk	Very low risk
Mood & Libido	Often poor	Stable
Long-term Safety	Liver, ocular, clot risks	Much cleaner

 

The Smart PCT Strategy for Modern Bodybuilders

• Base your PCT around Enclomiphene for a clean, controlled restart of natural testosterone. It is available as the product EncloSERM.
• Add an aromatase inhibitor (AI) like Alchemy to keep estrogen balanced during and after your cycle.
• Use dopaminergic support such as L-Dopa, 9-MBC, or Bromantane to regulate prolactin and mood.
• Finish with a natural testosterone booster like Test Elite paired with Alchemy to sustain libido and hormonal balance as you transition off EncloSERM.

 

Your Next Step: Upgrade to Modern PCT

We developed Encloserm specifically to replace outdated, side-effect-ridden PCT protocols. It delivers pharmaceutical-grade Enclomiphene Citrate that:

✅ Restores natural testosterone production
✅ Preserves free testosterone and IGF-1
✅ Prevents estrogen rebound
✅ Maintains mood, energy, and libido

→ Discover Encloserm: The Modern PCT Solution

Recommended Support Stack

• Core PCT: Encloserm (Enclomiphene)
• On-Cycle Estrogen Management: Alchemy
• Organ Protection: N2 Guard
• Liver Support (if using a methylated prohormone): TUDCA Elite
• Testosterone Booster: Test Elite

 

Final thoughts on Tamoxifen for PCT

While Tamoxifen has long been viewed as essential for post-cycle recovery, modern evidence shows it's no longer the most effective or safest option [4][5][6]. It may still serve a purpose for short-term control of estrogen during aromatising cycles, but using it as the centrepiece of PCT can hinder recovery and increase side effects. A far better approach for prohormone and AAS users is to manage estrogen directly with an aromatase inhibitor, then use Enclomiphene - the active isomer behind Clomiphene - to restart natural testosterone production without raising SHBG or suppressing IGF-1. This combination targets recovery at the root, not the symptoms.

For those who still choose to include Tamoxifen, pairing it with an AI is crucial to avoid estrogen rebound. But the smarter long-term strategy is to transition toward a cleaner SERM such as Encloserm, which restores testosterone naturally while supporting mood, libido, and hormonal stability.

 

References

[1] Birzniece V. et.al (2012): Gender differences in the neuroendocrine regulation of growth hormone axis by selective estrogen receptor modulators.

[2] Colletti R et.al (1989): Effect of Tamoxifen on Plasma Insulin-like Growth Factor I in Patients with Breast Cancer

[3] Willis KJ et.al : Hormonal effects of tamoxifen in Oligospermic men

[4] Fisher,B., Costantino,J.P., Redmond,C.K., Fisher,E.R., Wickerham,D.L., Cronin,W.M. and other NSABP contributors (1994) Endometrial cancer in tamoxifen-treated breast cancer patients: findings from the National Surgical Adjuvant Breast and Bowel Project

[5] IARC (1996) IARC Monographs on the Evaluation of Carcinogenic Risks to Humans. Some Pharmaceutical Drugs. IARC Scientific Publications, Vol. 66, IARC, Lyon.

[6] Bergman,L., Beelen,M.L.R., Gallee,M.P.W., Hollema,H., Benraadt,J., van Leeuwen,F.E. and Comprehensive Cancer Centres' ALERT Group (2000) Risk and prognosis of endometrial cancer after tamoxifen for breast cancer. Lancet, 356, 881–887.

[7] Greaves,P., Goonetilleke,R., Nunn,G., Topham,J. and Orton,T. (1993) Two-year carcinogenicity study of tamoxifen in Alderley Park Wistar-derived rats.

[8] Ogawa Y et.al (1998): Tamoxifen-induced fatty liver in patients with breast cancer

[9] Paganini-Hill et.al (2000): Eye problems in breast cancer patients treated with tamoxifen.

[10] Zhang et.al (1994): Tamoxifen blocks chloride channels. A possible mechanism for cataract formation.

[11] Kim E.D., McCullough A., Kaminetsky J., et al. (2015). Oral enclomiphene citrate raises testosterone and preserves sperm counts in obese hypogonadal men, unlike topical testosterone: restoration instead of replacement. BJU International, 116(2): 152–166. DOI: 10.1111/bju.13337

[12] Saffati G., et al. (2024). Safety and efficacy of enclomiphene and clomiphene for hypogonadal men. Translational Andrology and Urology, 13(9): 1913–1922. DOI: 10.21037/tau-24-238