In women, too much testosterone can cause insulin resistance and abdominal weight gain.
That’s why androgen excess is a factor in the weight gain associated with polycystic ovary syndrome (PCOS), menopause, and some types of birth control.
The link between testosterone and insulin resistance is most clear with the hormonal condition PCOS, in which high androgens made (mostly) by the ovaries cause insulin resistance and impair ovulation. Impaired ovulation, in turn, causes low progesterone and therefore robs the system of progesterone’s beneficial anti-androgen effect. This causes more high androgens and insulin resistance, creating a vicious cycle that I describe in my peer-reviewed paper.
Natural progesterone can help to lower androgens, improve insulin sensitivity, and break the cycle of PCOS. That’s why Professor Jerilynn Prior’s protocol of cyclic progesterone therapy for PCOS is currently undergoing a clinical trial.
👉 Tip: There’s no progesterone in hormonal birth control. Contraceptive drugs are progestins, many of which are androgenic or testosterone-like (see below).
Perimenopause and menopause
With the menopause transition, first progesterone, then estrogen drops away while androgens slightly increase before resuming their gradual decline with age (as happens in both men and women). The menopausal situation of relatively high testosterone paired with relatively low estrogen and progesterone causes a profound shift in fat distribution from gynoid (hourglass) to android (thicker waist and heavier upper body).
Menopausal hormone therapy (estrogen and progesterone) can have a beneficial anti-androgen effect and improve insulin sensitivity. For example, estrogen therapy directly improves insulin sensitivity and lowers testosterone by increasing sex hormone-binding globulin (SHBG), the protein that binds and inactivates testosterone. Progesterone indirectly improves insulin sensitivity by stimulating metabolic rate and lowering testosterone.
Taking testosterone or androgenic progestins can worsen insulin resistance and cause weight gain.
Androgenic (testosterone-like) progestins can cause insulin resistance and weight gain. They include levonorgestrel, norethindrone, and etonogestrel, found in many pills, Nuvaring, Mirena IUD, and the Nexplanon implant.
Anti-androgenic progestins can promote weight loss while being taken but rebound weight gain when they’re stopped. Anti-androgenic progestins include drospirenone, norgestimate, dienogest, and cyproterone.
The link between high testosterone and insulin resistance
There’s a bi-directional relationship between high testosterone and insulin resistance.
In one direction, insulin resistance or high insulin can stimulate ovarian cells to make more testosterone. That happens with PCOS and menopause.
In the other direction, testosterone can cause or worsen insulin resistance. That happens with PCOS, menopause, and androgenic progestins.
And all of it can lead to weight gain, acne, facial hair, irregular periods, and a long-term risk of diabetes.
There are two parts to the solution: 1) reverse insulin resistance and 2) lower androgens, which, in turn, can improve insulin resistance.
- To reverse insulin resistance, follow the recommendations in my updated blog post Reverse insulin resistance in 4 easy steps.
- To lower androgens, identify and correct your type of PCOS so you can start to ovulate and make estradiol and progesterone (both have anti-androgen effects). You can also consider cyclic progesterone therapy or other natural anti-androgen supplements. If you are already in menopause (and can, therefore, no longer ovulate), consider taking bioidentical estrogen and progesterone.