The Common Hair-Loss Remedy Linked With Depression & Suicide

In saving your hair, you might lose more than that:

Finasteride & your brain

Finasteride is a commonly-prescribed hair-loss remedy.

How it works:

• It’s a 5α-reductase inhibitor
• That means it inhibits 5α-reductase
• 5α-reductase is an enzyme that helps convert testosterone to dihydrogen testosterone (DHT), its much more potent form
• DHT is the one that tells your head hair to fall out, and your body hair to grow thicker
• So reducing DHT means increasing head hair and decreasing body hair, which is usually what someone taking finasteride wants

There are other reasons finasteride is prescribed, of which the main one is the treatment of benign prostatic hyperplasia (BPH).

We’ve talked about its use as a hair loss remedy, here: Hair-Loss Remedies, By Science

We’ve talked about its use to treat BPH, here: Prostate Health: What You Should Know

It works very well for both of those things. However…

New analyses of old data reveals that finasteride has been consistently linked to depression and suicide for more than two decades.

The increase in risk depends on which data we use, which analytical method we use, and which risk factor we’re looking at (depression, suicidal ideation, suicide attempts, completed suicide), but doing some rough math of our own looking at their data table, we can say the overall increase in risk of these adverse psychiatric events appears to be around 533%.

So, why is this the first we’re hearing about it? According to the recently-published work that we’ll link below, it’s because the manufacturer, Merck, and the FDA repeatedly ignored warning signs in order to keep selling the product.

The FDA only recognized depression as a possible side effect in 2011 and added suicidal thoughts to the label in 2022, despite internal evidence from 2010 suggesting wider harm.

You may be wondering: is the depression/suicidality perhaps incidental to the midlife age at which finasteride is commonly prescribed?

And the answer is: no, this was controlled for using data from 8 large studies; the association remains regardless of age:

❝Assuming a null hypothesis (finasteride does not affect mood) and a 50% chance of 1 result against this hypothesis, the probability of getting all 8 studies concluding against the null hypothesis by chance is 0.5⁸ = 0.0039.❞

Furthermore, the mechanism of harm appears to be unrelated to its hormonal effects, so the DHT-blocking activity itself doesn’t seem to be the issue either. Rather, it’s believed to be because inhibiting 5α-reductase enzyme also disrupts neurosteroids like allopregnanolone, which are crucial for mood regulation and cognitive function.

Further studies cited in this research show long-term brain effects such as neuroinflammation and adverse hippocampal changes, too, but the science is younger for that.

You can find the paper itself, here: Failing Public Health Again? Analytical Review of Depression and Suicidality From Finasteride

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Take care!