Gonal-F vs. Follistim: Which One is Better?
When navigating fertility treatments, especially involving injectable medications, two names often surface: Gonal-F (follitropin alfa) and Follistim (follitropin beta). Both are recombinant forms of follicle-stimulating hormone (FSH) designed to stimulate ovarian follicle development. But how do they compare, and are they effective for all women?
Gonal-F and Follistim: What's the Difference?
Structurally, Gonal-F and Follistim are nearly identical, differing slightly in their amino acid sequences. This minor variation doesn't translate into significant differences in efficacy or safety. Studies have shown that both medications are similarly effective in stimulating ovarian response. (GoodRx)
However, what most people don’t realize is that clinical trials for these medications often exclude women with endometriosis, PCOS, and those over 35 years old—the very groups that often struggle the most with infertility. That means the dosing and effectiveness of these drugs may not be optimized for these women.
How Clinical Trials Exclude Women Who Need Help the Most
Most clinical studies on Gonal-F and Follistim were designed to evaluate these drugs in women with uncomplicated infertility, meaning they do not have underlying reproductive conditions like PCOS or endometriosis. Here’s how:
1️⃣ Women Over 35 Are Often Excluded
Many clinical trials cap the age limit at 38, with an average participant age closer to 32.
This is because ovarian reserve naturally declines with age, making it harder to measure the true effectiveness of these medications in older women.
However, many women over 35 rely on these drugs, even though they were not specifically tested in this population. (Health Canada Drug Monograph)
2️⃣ Women with Endometriosis Are Left Out
Women with Stage III or IV endometriosis are frequently excluded from clinical trials for FSH-based medications like Gonal-F and Follistim.
Endometriosis affects egg quality, implantation, and inflammation in the reproductive tract—factors that these medications do not address.
Studies show that women with endometriosis respond less effectively to gonadotropins. (PMC)
3️⃣ Women with PCOS Are Underrepresented
PCOS patients often have irregular ovulation and an excessive number of follicles, making them more prone to Ovarian Hyperstimulation Syndrome (OHSS) when using gonadotropins.
Many studies deliberately exclude women with PCOS to avoid unpredictable responses and complications.
However, these women still end up being prescribed these medications, despite a lack of proper clinical data for their condition. (Fertility and Sterility)
👉 The Bottom Line: Women who actually need these medications the most weren’t included in many of the clinical trials that led to their FDA approval. That means the standard protocols may not be the best fit for women over 35, or those with PCOS and endometriosis.
What This Means for Your Fertility Treatment
If you’ve been prescribed Gonal-F or Follistim, but have a condition like endometriosis, PCOS, or are over 35, you may need a more tailored approach than standard dosing guidelines. That’s where we come in.
At our clinic, we take a comprehensive and individualized approach to fertility care:
✅ Comprehensive Assessment – We don’t assume a one-size-fits-all protocol works. We analyze egg quality, hormone levels, uterine health, and metabolic factors to create a customized plan for you.
✅ Acupuncture for Fertility – Research-backed acupuncture can increase blood flow to the ovaries and uterus, improve implantation rates, and regulate hormones to enhance conception.
✅ Functional Medicine Approach – We go beyond medication by addressing inflammation, gut health, thyroid dysfunction, and adrenal fatigue, all of which play a role in fertility.
✅ Personalized Nutrition & Supplements – Not all fertility supplements are created equal. We develop a customized plan based on your lab results, ensuring you get the right nutrients to optimize egg and sperm health.
✅ Stress & Hormone Regulation – Chronic stress can disrupt ovulation and implantation. We integrate stress reduction techniques, mind-body therapies, and adaptogenic herbs to support a balanced reproductive system.
Are You Wasting Time with Standard Fertility Protocols?
If you’ve been using Gonal-F or Follistim without success, or if you have a history of PCOS, endometriosis, or are over 35, it’s time to get a personalized approach that actually works.
📞 Schedule a consultation today and let’s create a fertility plan that’s designed for YOUR body—not just a standard protocol from outdated clinical trials.
Because your path to pregnancy should be built around YOU. 💕
References
GoodRx. (n.d.). Follistim vs. Gonal-F: What’s the Difference? Retrieved from https://www.goodrx.com/conditions/fertility/follistim-vs-gonal-f
Health Canada. (2017). Gonal-F (follitropin alfa) – Product Monograph. Retrieved from https://pdf.hres.ca/dpd_pm/00039076.PDF
Harb, H., Alabed, H., & Gallos, I. (2013). Impact of endometriosis on IVF outcomes: A systematic review and meta-analysis. Journal of Obstetrics and Gynaecology Research, 39(1), 133–140.
Legro, R. S., Brzyski, R. G., Diamond, M. P., Coutifaris, C., Schlaff, W. D., Casson, P. R., ... & Zhang, H. (2014). Letrozole versus clomiphene for infertility in the polycystic ovary syndrome. New England Journal of Medicine, 371(2), 119–129.