FSH‑rec (Gonal‑F / Puregon)
Recombinant FSH (CHO-expressed) – selective Sertoli FSHR stimulus, NO LH activity. AAS-PCT niche: azoospermia recovery + Sertoli support alongside HCG LH. Expensive (€300+/75 IU vial EU). Cross-frame: future peptide library will add `fsh-rec-peptid`.
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WHAT IS FSH-REC (GONAL-F / PUREGON)?
Detailed overview
FSH-rec (recombinant follicle-stimulating hormone) is a biotechnologically manufactured glycoprotein expressed in Chinese Hamster Ovary (CHO) cell line. Two main brand names: Gonal-F (Merck Serono, EMA 1995, FDA 1997) and Puregon/Follistim (Organon, EMA 1996, FDA 1997). Recombinant production resolved the purification problems tied to urinary source (LH contamination in the Pergonal era, prion risk in the vCJD context) – Gonal-F + Puregon provide pure FSH activity with NO LH side-activity. **AAS-PCT context**: FSH-rec's niche position arises when Sertoli-selective stimulus is required. Typical indication: azoospermia recovery after a hard-suppression long cycle (>20 weeks) or 'blast-and-cruise', where Leydig functionality can be preserved (HCG mid-cycle protocol or endogenous low-LH restart) BUT Sertoli FSH-receptor activity doesn't return without a separate stimulus. FSH-rec then acts as a specific Sertoli-FSHR activator → spermatogenesis restart, inhibin-B rise. **Cross-frame note**: this is the `-perf` suffix entry; the future peptide library batch will add the `fsh-rec-peptid` entry (fertility-clinic framing – IVF male-factor + ICSI sperm-prep protocol). WADA-banned year-round (S2 Peptide Hormones).
Mechanism
Recombinant FSH (CHO-expressed) – selective Sertoli FSHR agonist, NO LH activity
Dosing (PCT azoospermia recovery)
75-150 IU EOD × 4-12 weeks
Half-life
~24-36 hours (recombinant)
Onset
Inhibin-B rise 2-4 weeks, sperm count rise 3-9 months
Legal status
EMA Rx Gonal-F (1995) + Puregon (1996), FDA Rx (1997), WADA S2 (banned)
Data console
Lab data
Safety
Side effects, stop signs, contraindications
Side effects · 7
- Injection-site reactions: redness, pain, itching, swelling and bruising at the SC injection site (the most common adverse effect).
- Headache, the most common systemic complaint during treatment.
- Hypersensitivity / allergic reactions: rash, urticaria, as a response to residual CHO-cell-derived proteins; rarely severe anaphylactic reactions may occur.
- Gastrointestinal symptoms: nausea, abdominal pain, diarrhea and bloating.
- In men (on long HCG + FSH-rec protocols) gynecomastia and acne may occur, mainly due to the testosterone and estrogen rise driven by the co-administered HCG, not by FSH itself.
- Thromboembolic events (deep vein thrombosis, pulmonary embolism) are a rare but serious risk, mainly in the presence of predisposing factors (thrombophilia, obesity, prior thrombosis).
- Ovarian hyperstimulation syndrome (OHSS) – relevant only in female fertility use: abdominal distension, ovarian enlargement, in severe cases fluid accumulation; not applicable to male protocols.
Contraindications · 6
- Pituitary or hypothalamic tumor, or undiagnosed, untreated endocrine disorder (thyroid, adrenal).
- Hypersensitivity to follitropin, to CHO-cell-derived residual proteins, or to any excipient of the product.
- Tumors of the reproductive organs, or a hormone-dependent tumor of the testes (or in women the ovary, breast, uterus).
- Primary testicular failure (e.g. Klinefelter syndrome, Y-chromosome AZF microdeletion) – here the Sertoli defect is primary and FSH-rec is ineffective.
- Active thromboembolic disease or high thrombotic risk (severe thrombophilia, recent thrombosis).
- WADA S2.2 prohibited substance – banned year-round for competing athletes (both in- and out-of-competition).
Related Performance Compounds
Same therapeutic category
Studies
Related research and clinical findings
Fertility outcomes in male adults with congenital hypogonadotropic hypogonadism treated during puberty with human chorionic gonadotropin and recombinant follicle stimulating hormone.
Grob F, Keshwani R, Angley E
Congenital combined pituitary hormone deficiency patients have better responses to gonadotrophin-induced spermatogenesis than idiopathic hypogonadotropic hypogonadism patients.
Mao J, Xu H, Wang X, Wu X, Nie M, Zhang H, Han B, Liu Z, Zhang K, Lian S, Lu S, Wang X, Chen N, Sun B, Liu J, Cui Q
Addition of recombinant follicle-stimulating hormone to human chorionic gonadotropin treatment in adolescents and young adults with hypogonadotropic hypogonadism promotes normal testicular growth and may promote early spermatogenesis.
Zacharin M, Sabin MA, Nair VV, Nicolaides R
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The information here is for educational and scientific purposes only. Performance-enhancing compounds (AAS, prohormones, stimulants, doping agents) are illegal without prescription in Hungary and most of the EU, and carry serious health and legal risks. WADA bans them in competitive sport. This is NOT a usage guide, and we do not encourage any illegal use. If you do use them, medical supervision and regular bloodwork are ESSENTIAL. Severe endocrine, cardiovascular, hepatic and psychiatric side effects are possible.