Finasteride and Testosterone: Does It Lower or Raise Your T?

This page explains what that means for your body, how dutasteride compares, and why "low T" feelings on finasteride are a separate question. We do not give doses. A clinician decides if the drug suits you.

How finasteride works on testosterone

Your body makes testosterone, the main male hormone. An enzyme, a body chemical that speeds up a reaction, turns some of it into DHT. The enzyme is called 5-alpha reductase. Finasteride blocks one type of it.

The label puts it this way: finasteride "is a specific inhibitor of steroid Type II 5α-reductase, an intracellular enzyme that converts the androgen testosterone into 5α-dihydrotestosterone (DHT)" (DailyMed: Propecia label). In plain words, it slows the change from testosterone to DHT.

DHT is what shrinks hair roots in men with pattern hair loss. The label says "the balding scalp contains miniaturized hair follicles and increased amounts of DHT compared with hairy scalp" (DailyMed: Propecia label). Less DHT means less shrinking. That is the whole point of the drug.

Does finasteride lower testosterone?

No. The label's numbers point the other way. When less testosterone is turned into DHT, a little more of it stays in the blood. That is why the label reports a rise of about 15% in average testosterone.

Here is what the label reports, side by side:

The phrase "within the physiologic range" matters. It means the levels stayed inside what is normal for healthy men. The label does not describe a jump into a high range.

Does finasteride increase testosterone?

A little, on average, as the table shows. But this is not a way to raise testosterone on purpose. The rise is small, and it stays in the normal range. No finasteride label lists low testosterone as a use. If your goal is more testosterone, that is a different treatment. Our testosterone price page lists the programs that treat low T, with prices.

Estradiol, a form of estrogen, also rose by about the same amount. Some men worry that more estrogen could mean breast changes. The label does list breast tenderness and breast growth as side effects, though rare. Tell your prescriber about any breast lump, pain or nipple discharge.

Does dutasteride lower testosterone?

No. Dutasteride (Avodart) is the other drug in the same class. It blocks both types of the enzyme, not just one. So it cuts DHT even more than finasteride does, and testosterone rises a bit more.

The Avodart label says "The median increase in serum testosterone was 19% at both 1 and 2 years, 26% at 3 years, and 22% at 4 years, but the mean and median levels remained within the physiologic range" (DailyMed: Avodart label, read 14 Nov 2026). The median is the middle value of the group.

Avodart is approved for an enlarged prostate, not for hair loss. Some programs still prescribe it for hair; that is a use the FDA has not approved. Our dutasteride for hair loss guide covers that choice, and finasteride vs dutasteride compares the two.

If testosterone goes up, why do some men feel "low T" symptoms?

This is the part that confuses people. Some men on finasteride report lower sex drive or weaker erections. Those are also classic signs of low testosterone. But the label shows testosterone does not fall.

The likely link is DHT, not testosterone. DHT plays a part in sexual function, and finasteride lowers it. The label's trials did find a small gap. Decreased libido showed up in 1.8% of men on finasteride against 1.3% on a dummy pill. Erectile dysfunction showed up in 1.3% against 0.7%.

MedlinePlus lists the same kinds of effects and adds a caution: "decreased sexual desire, ejaculation problems, and inability to have or maintain an erection may occur during and after your treatment is stopped" (MedlinePlus: finasteride, read 14 Nov 2026). Our finasteride side effects guide has the full table, and post-finasteride syndrome covers effects that last after stopping.

If you feel off, a blood test can settle the testosterone question. A normal result points away from low T. Then your prescriber can look at the drug, the dose or another option.

Finasteride and TRT together

Some men take testosterone treatment (TRT) and also worry about their hair. More testosterone can mean more DHT, since the body turns some of it into DHT. That can speed up pattern hair loss in men who are prone to it.

Finasteride is sometimes added for that reason. It does not cancel the testosterone. It only slows the change into DHT. Whether to combine them is a call for the prescriber who manages your TRT. Our TRT hair loss guide explains what the testosterone labels say about hair.

What the American Academy of Dermatology says

The AAD, the main US group of skin doctors, sees finasteride as a standard hair loss pill. It says "Finasteride has been shown to slow down further hair loss in about 80% to 90% of men taking it" (AAD: male pattern hair loss treatment, read 14 Nov 2026). It also notes side effects, so a dermatologist will ask about your health before prescribing.

What finasteride costs

Generic finasteride is cheap. The lowest price per tablet we track is $0.83 at Strut Health. The cheapest hair loss plan overall is Keeps at $14 a month, as checked November 14, 2026. Every plan and its source is on our finasteride price page.