Long Story Short:
- Intramuscular injections of Testosterone and Progesterone are effective in reducing sperm production, with 4 of 256 partners becoming pregnant.
- Intramuscular injections of Testosterone and Progesterone are not safe with adverse effects of depression, mood disorders, acne, and increased libido.
- The infertility effects are reversible, in 95% of participants.
- The study was terminated before completion because the benefits did not outweigh the risks.
Condoms, withdrawal and vasectomies are the only forms of contraception men have had the luxury of using, and now in a new study published in the Journal of Clinical Endocrinology & Metabolism. scientists are trying to develop a male contraceptive shot. Whats in it? Testosterone (T) and Progesterone, yes the same progesterone that fertile women produce. (Note: Men produce progesterone too, but much less than women). Testosterone, the male hormone, we sometimes thinks means a man in strong and fertile. This would be true if they’re producing it on their own, endogenously, assuming other hormones are in equilibrium.
But similar to men who take steroids/performance enhancing drugs/T-shots, they shut down their hypothalamus and pituitary from producing hormones FSH and LH which are responsible for producing sperm and testosterone, which explains why their testicles atrophy. So they may appear strong but their ability to produce sperm is decreased, and essentially may need other drug interventions to reverse those effects.
In this study, they were working with the same thought process but instead giving men mega-doses of testosterone was unethical, and so instead they added progesterone. Progesterone allowed them to use less T in order to reduce sperm production, to hopefully reduce adverse effects.
The results: It significantly reduced pregnancy rates, with 4 pregnancies occurring among the 266 male partners, and about 95% of the participants regained their fertility. Although I’d like to say scientists have found a new form of male contraception, in fact the study produced enough adverse effects to terminate the study, which included depression and mood disorders, pain at the injection site, acne, and increased libido (not sure that was a side effect, more like an expected effect 😏), and overall the risks outweighed the benefits.
Even the authors of this paper admit the pharmacokinetics of testosterone, progesterone and their interactions with other hormones and body systems is very complex and oftentimes difficult to predict. This is why I am always suspect of pharmaceuticals that have such a steering effect on hormones and their production, including birth control. Although there are no herbs or nutrients for birth control, I still trust the first-line approach approach to normalizing and managing hormones should first be through an integrative, functional and naturopathic approach. These methods using lifestyle, herbs, nutrients, and acupuncture oftentimes are enough to help with endocrine issues. Also to note, I have seen many patients who altered their hormonal levels with testosterone and steroids and the long term effects (weeks, months and years later) were not worth the short term esthetic benefits.
- Hermann M. Behre, Michael Zitzmann, Richard A. Anderson, David J. Handelsman, Silvia W. Lestari, Robert I. McLachlan, M. Cristina Meriggiola, Man Mohan Misro, Gabriela Noe, Frederick C. W. Wu, Mario Philip R. Festin, Ndema A. Habib, Kirsten M. Vogelsong, Marianne M. Callahan, Kim A. Linton, and Doug S. Colvard. Efficacy and Safety of an Injectable Combination Hormonal Contraceptive for Men. Journal of Clinical Endocrinology & Metabolism, October 27, 2016 DOI: 10.1210/jc.2016-2141