Hair loss from the pill: What’s really going on

Androgenic Progestins: What Is and Isn't True

Almost every guide on this topic divides pills into two camps: androgenic progestins such as levonorgestrel or norethindrone, which are said to damage hair, and antiandrogenic ones such as drospirenone or dienogest, which are said to protect it. This classification is not incorrect, but it does not go as far as it promises.

This is exactly what Zimmerman and colleagues examined in their meta-analysis. The result: The type of progestin did not affect the reduction in total and free testosterone. Something else differed, namely the extent to which SHBG increased. With second-generation progestins and low-dose ethinyl estradiol, the increase in SHBG was smaller. However, active androgens decreased in all groups.

For you, this means: If your hair falls out while taking a pill with levonorgestrel, the obvious conclusion is not automatically correct. Androgenic effects do not explain it in most cases. What explains it much better is timing.

Telogen Effluvium: Why Hair Loss Is Delayed

Your hair does not grow evenly, but in cycles. Each individual hair goes through a growth phase lasting years, a short transitional phase, and a resting phase of several months, at the end of which it falls out. Normally, these cycles are distributed across the head, which is why you do not even notice the change.

A hormonal event can send many follicles into the resting phase at the same time. This is telogen effluvium. And because the resting phase lasts several months, you do not see the result immediately. In the review by Asghar and colleagues, hair loss typically begins two to three months after the trigger, and in medication-induced forms, usually after about twelve weeks of use.

This delay is the reason it feels like it came out of nowhere. You switched pills four months ago, everything was fine for three months, and then suddenly there are hairs everywhere. It feels like an acute problem, but it is the delayed reckoning for a change that happened long ago.

Distinguishing this from androgenetic alopecia is medically important because the two conditions progress completely differently. With telogen effluvium, you lose many hairs diffusely across the entire head, but the density recovers. With androgenetic alopecia, fewer hairs fall out, but they become thinner and shorter at the part and on top of the head over the years because the follicles shrink. In the so-called wash test, telogen effluvium shows more than 100 fallen hairs with less than 10 percent fine hairs, while androgenetic alopecia shows fewer than 100 hairs with more than 10 percent fine hairs (Asghar et al., 2020). Both can also occur at the same time.

If your hair loss began after stopping the pill and not during use, the same mechanism applies, only at a different time. We have a separate post about this: Hair loss after stopping the pill.

Which pill for hair loss? The honest answer

This is where it gets uncomfortable, because widespread expectations and the body of research diverge. Antiandrogen pills are indeed used to treat skin and hair symptoms caused by androgens, but the evidence for this primarily concerns unwanted body hair growth, not scalp hair.

The Cochrane review on hirsutism, involving 157 studies and 10,550 women, concludes that for mild hirsutism, there is limited-quality evidence for the effectiveness of oral contraceptives, and that additional cyproterone acetate reduced hair scores more significantly (van Zuuren et al., 2015). The authors rate the certainty of this statement as low.

The situation is different for hair loss on the head. The Cochrane review on androgenetic alopecia in women, involving 47 studies and 5,290 participants, makes no statement at all about the effectiveness of cyproterone acetate, but calls for further controlled studies. Finasteride was no more effective than a placebo in this review. Topical minoxidil is supported by evidence, although mostly of moderate to low quality, and there was no difference between 2% and 5% (van Zuuren et al., 2016).

The practical consequence: A pill is not a hair growth aid. Switching may make sense if several symptoms occur together, but the decision should be left to medical professionals and requires a diagnosis, not an internet list. And importantly: Do not stop taking the pill on your own, because stopping it can trigger the next wave of hair loss.

What the pill depletes in terms of nutrients

This part is rarely discussed, and it is the lever you can actually use to do something yourself. In a review of oral contraceptives and nutrient requirements, Palmery and colleagues found lower levels of folic acid, vitamin B2, vitamin B6, vitamin B12, vitamin C, vitamin E, magnesium, selenium, and zinc while taking the pill (Palmery et al., 2013).

The reason this matters particularly for hair lies in the tissue. The hair follicle is one of the structures with the highest cell division rate in the human body. Where new cells are constantly being formed, a shortage of supply becomes apparent sooner than in slowly working tissue. The chain is therefore indirect but plausible: The pill lowers the levels, the supply becomes scarcer, and the follicle reacts as one of the first. The data on this comes from a review, not a controlled study, and that is how you should interpret it.

The roles of the individual nutrients, on the other hand, are well documented. According to the EFSA, zinc and selenium contribute to the maintenance of normal hair. Vitamin B6 contributes to the regulation of hormonal activity and the reduction of tiredness and fatigue, while folate and magnesium also help reduce tiredness. These are authorized statements about nutrient functions, not promises against hair loss, and that is exactly what they are intended to be.

One nutrient is deliberately missing from this list, even though it is the most important one for hair loss: iron. Ferritin is the laboratory value you should know first in the case of diffuse hair loss, and iron should not be part of a basic supply without proven deficiency. Have it measured instead of guessing.

What you can do now

The first step is unspectacular and helps the most: Write down when you started, switched, or stopped taking the pill, and when the hair loss began. If there is a gap of two to three months between these events, you most likely have telogen effluvium, which means something that can recover.

Second: Have the values checked that really mean something in the case of diffuse hair loss. These include ferritin, a complete blood count, thyroid values, and, depending on your history, androgens. Third: Give your hair time and support basic supply instead of buying miracle cures. Hair grows about one centimeter a month, so visible changes will therefore take months, not weeks.

And fourth, because it is often overlooked: Gentle care does not prevent hormonal hair loss, but it does prevent additional mechanical breakage. Less heat, less pulling, no aggressive bleaching during a phase of hair loss.

You can find an overview of all causes of diffuse hair loss in women and the growth phases in the main article Hair loss in women.

When you should have it checked by a doctor

This is the case if the hair loss lasts longer than six months, if bald patches or a visibly widening part appear, if you also experience cycle irregularities, increased body hair, or acne, or if you are considering switching pills. All of these require a diagnosis.

If you want to sort out what is even an option for you beforehand, you can discuss it in a free initial consultation with one of our doctors. And if you are already considering stopping the pill, it is worth taking a look at our Guide to stopping the pill beforehand.

Conclusion

Hair loss from the pill is real, but it works differently than most guides claim. The combined pill significantly lowers your free androgens, which is more likely to be protective against androgen-related hair loss. In most cases, it is the hormonal transition itself that causes hair loss, as telogen effluvium with a two- to three-month delay, and therefore temporarily.

The classification into androgenic and antiandrogenic pills explains less than is attributed to it. And a pill is not a hair growth aid: The evidence for antiandrogenic preparations for scalp hair is thin, with topical minoxidil being the most proven. What you can influence yourself is the nutrient foundation and the time at which you know your levels. Everything else belongs in the hands of doctors, and impatience is the worst guide when it comes to hair.