Medicine 4: Progestin

Medicine 4: Progestin

What is it?

Progestins, synthetic compounds emulating the action of progesterone, serve a pivotal role in various medical applications, spanning from contraception to postmenopausal hormone replacement therapy. These medications interact with progesterone receptors, exhibiting distinct effects based on their generational classification or structural composition.¹

How does it work?

In women with primary dysmenorrhea, OCPs thin the endometrium, thereby reducing the amount of bleeding and inhibiting the metabolism of arachidonic acid to prostaglandin, effectively relieving cramping and pain.²

What is the efficacy?

Method: Studies were done which included a large randomized controlled trial and a systematic review with network meta-analysis, both focusing on the use of the progestin dienogest for dysmenorrhea. In the trial, women were randomly assigned to receive either dienogest 1 mg daily or a placebo, with pain relief and side effects tracked over the treatment period. The meta-analysis pooled data from multiple clinical trials comparing dienogest and low-dose estrogen–progestin pills.^3,4

Results: All DNG arms were superior to the placebo arm in terms of the change from baseline in the dysmenorrhea score. The results suggest an equal or greater effect of DNG 1 and 2 mg/d in relieving pain, when compared to the reference drug. The meta-analysis showed that continuous dienogest regimens often provided greater pain improvement than standard cyclic hormone regimens, especially in secondary dysmenorrhea.

Conclusion: Overall, progestin is an effective and well-tolerated option for managing dysmenorrhea, offering significant pain relief with mostly mild side effects.

Side-effects:

Short-term effects: Unscheduled bleeding and changes in menses

Long-term effects: Hirsutism, and an increased prevalence of follicular ovarian cysts.¹

References

1. Edwards M, Can AS. Progestins. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan [cited 2025 May 16]. Available from: https://www.ncbi.nlm.nih.gov/books/NBK563211/

2. Casper RF. Progestin-only pills may be a better first-line treatment for endometriosis than combined estrogen-progestin contraceptive pills. Fertility and sterility. 2017 Mar 1;107(3):533-6.

1. Lessey BA, Young SL. Evaluation of the efficacy, safety, and clinically recommended dose of dienogest in the treatment of primary dysmenorrhea: a randomized, double-blind, multicenter, placebo-controlled study. Fertil Steril. 2019 Dec;112(6):1093-1101. doi: 10.1016/j.fertnstert.2019.08.013.

2. Iwata M, Oikawa Y, Shimizu Y, Sakashita N, Shoji A, Igarashi A, Osuga Y. Efficacy of Low-Dose Estrogen–Progestins and Progestins in Japanese Women with Dysmenorrhea: A Systematic Review and Network Meta-analysis. Advances in therapy. 2022 Nov;39(11):4892-909.