Finasteride and Fertility: What to Know When Trying for a Baby
Last reviewed on 12 July 2026. We review our treatment guides every six months to keep them accurate.
Finasteride, sold under the brand name Propecia, is one of the main medicines used for male pattern hair loss, and many men take it for years. If you are trying for a baby, two separate questions tend to come up, and it helps to keep them apart. The first is whether finasteride affects your own fertility, mainly your sperm. The second is whether the small amount of finasteride that reaches semen could harm a pregnancy your partner is carrying. This guide covers both, with the emphasis on the first, because that is the question most men on finasteride are really asking. It is general information rather than medical advice, so please speak to your GP or a fertility specialist about your own situation.
For an independently maintained summary, the NHS page on fertility and pregnancy while taking finasteride is a good starting point. It is reviewed and updated periodically, so it stays current between our own reviews.
How finasteride can affect male fertility
Finasteride works by lowering dihydrotestosterone (DHT). DHT has a role in the prostate and the seminal vesicles, the glands that produce most of the fluid in semen, so the most consistent effect finasteride has on the male reproductive system is a reduction in the volume of semen. In the manufacturer's data for the 1mg hair loss dose, a small number of men reported reduced ejaculate volume, slightly more than on a dummy tablet. For most men this is not something they notice, and it does not prevent conception.
The effect on the sperm themselves, the count and how well they move, is smaller and less predictable. In most men taking finasteride, any change in sperm count or motility is slight or absent. There are, however, well documented cases where finasteride appeared to lower sperm counts, and this seems to matter most in men who already have a low count. In one study of men attending a fertility clinic who happened to be taking finasteride, stopping it was followed by a large rise in sperm count, on average around eleven-fold, and among the men with the very lowest counts more than half rose into the normal range after stopping. That study looked at only 27 men, most of whom had been taking finasteride for several years, so it tells us more about men who already have fertility problems than about the average user.
It is worth being honest about the strength of this evidence. Much of it comes from case reports and small observational studies rather than large randomised trials. The overall picture is of a real but uncommon effect, concentrated in men who already have reduced fertility, rather than a drug that routinely causes infertility. Where finasteride does reduce semen quality, the change is usually reversible. Both the NHS and the manufacturer's product information note that sperm quality generally returns to normal after the medicine is stopped, typically over a few months, which reflects the roughly three-month cycle the body takes to produce new sperm.
Finasteride in semen: is it a risk to a pregnant partner?
This is the question people most often confuse with the fertility one, so it is worth setting out clearly. The well established safety concern with finasteride is that a pregnant woman should not be exposed to it, because it can interfere with the normal development of a male baby's genitals. That warning is about the medicine reaching the woman directly, for example by handling crushed or broken tablets, rather than about semen. Whole tablets are coated to prevent this. This is the real origin of the fear about finasteride and birth defects, and it is worth being precise: the concern is direct exposure of a pregnant woman, not a man taking finasteride while trying for a baby. Paternal use, meaning the father taking it, is not expected to cause birth defects.
Only a very small amount of finasteride passes into semen. The manufacturer's testing detected less than 0.001% of a 1mg dose in the seminal fluid of men taking it. On the evidence to date, regulators and the product information conclude that this tiny amount is not expected to pose a risk to a male baby carried by a partner. The NHS puts it plainly: if you are pregnant and your partner takes finasteride, it is very unlikely to cause any harm to you or the baby. The manufacturer still suggests using a condom if your partner is pregnant or might become pregnant, but the NHS notes that most experts consider this a cautious extra rather than a necessity. If it is on your mind, it is a reasonable thing to raise with your doctor.
Sexual side effects, mood and the MHRA warnings
Sexual side effects matter when you are trying to conceive, because they can affect conception directly. Finasteride is recognised to reduce sex drive and to make erections more difficult in a minority of men. For most, these ease after stopping, and often even while continuing, but a smaller number report problems that persist after the medicine is stopped, a pattern sometimes discussed under the heading of post-finasteride syndrome. Whether finasteride is the cause of persistent symptoms remains debated, but the concern is taken seriously by regulators.
In 2024 the UK medicines regulator, the MHRA, introduced patient alert cards for finasteride highlighting psychiatric and sexual side effects, and in May 2026 it strengthened the warnings further. The current position is that finasteride is associated with depression, suicidal thoughts and sexual dysfunction that may persist after treatment is stopped, and that sexual dysfunction may in turn contribute to low mood. A precautionary warning has also been added for dutasteride, a related medicine. Anyone taking finasteride who develops low mood or thoughts of self harm is advised to stop and seek medical advice promptly. You can read the current position in the MHRA's drug safety update.
Should you stop finasteride before trying to conceive?
There is no blanket rule that every man must stop finasteride before trying for a baby. For a man with no known fertility problem, the medicine is very unlikely to prevent conception, and stopping it usually means hair loss resumes, with any ground gained gradually lost. The picture changes if there is difficulty conceiving. Fertility specialists commonly advise a man who has unexplained infertility, or an abnormal semen analysis, and who is taking finasteride, to stop the medicine and repeat the semen test after about three months, the time it takes to produce a fresh cycle of sperm. This is general specialist practice rather than an instruction from us, and the right course for you is a decision for your GP or a fertility clinic, who can look at your own results.
Options while you are trying for a baby
If you would rather not take oral finasteride while trying to conceive, there are a few directions to discuss with a clinician, none of which is clearly the right answer for everyone:
Pausing treatment. The simplest option is to stop finasteride while trying to conceive and restart later. The trade off is that hair loss tends to resume when the medicine is stopped, and any regrowth can gradually be lost.
Minoxidil. Minoxidil is a topical hair growth stimulant that does not act on DHT, so it sits outside the finasteride fertility question. It is a common choice for men who want to keep treating hair loss without an oral DHT blocker, though it is a different medicine with its own considerations.
Topical finasteride. Applying finasteride to the scalp leads to lower levels in the bloodstream than the tablet, and it is sometimes suggested for that reason. The important caveat is that absorption is lower but not zero, and there is no good evidence that it is safer specifically for conception, so it should not be assumed to be a risk free version. Any use is off-label and a matter for a clinician.
Frequently asked questions
Can I take finasteride while trying for a baby?
For most men with no fertility problem, finasteride is very unlikely to prevent conception, and the small amount that reaches semen is not expected to harm a baby your partner is carrying. It is not automatically necessary to stop. The main reasons to reconsider are difficulty conceiving, an abnormal semen test, or sexual side effects that are affecting you. It is worth talking it through with your GP.
Does finasteride lower my sperm count?
In most men it has little or no effect on sperm count, though it commonly reduces the volume of semen slightly. In a minority, particularly men who already have a low count, it can lower sperm numbers, and counts have improved after stopping. The evidence is mostly from small studies and case reports. If you are concerned, a semen analysis is the way to find out where you stand.
Is finasteride in semen dangerous to my pregnant partner?
The amount of finasteride that reaches semen is very small, less than 0.001% of a tablet's dose, and regulators conclude it is not expected to pose a risk to a male baby or to cause birth defects. The NHS says harm is very unlikely. The manufacturer still suggests a condom if your partner is pregnant, but most experts regard this as a cautious extra rather than a necessity. The separate, firm rule is that a pregnant woman should not handle crushed or broken tablets.
How long after stopping finasteride does fertility recover?
Where finasteride has affected semen quality, it usually improves after stopping, generally over a few months. This reflects the roughly three-month cycle the body takes to produce new sperm, which is why fertility specialists often re-test a semen sample about three months after the medicine is stopped.
Is topical finasteride safer if we are trying to conceive?
Topical finasteride puts less of the drug into the bloodstream than the tablet, but absorption is not zero, and there is no good evidence that it is safer specifically for conception. It should not be assumed to be risk free for this purpose. If you are weighing it up, discuss it with a clinician, as any use is off-label.
The bottom line
For a man with no fertility problem, finasteride is very unlikely to stand in the way of conceiving, and the trace that reaches semen is not expected to harm a pregnancy. Its clearest effect on the male side is a small reduction in semen volume, with an uncommon and usually reversible effect on sperm count that matters most in men who already have a low count. Where there is difficulty conceiving, stopping finasteride and re-testing after about three months is a common specialist step. Sexual and mood side effects, now covered by strengthened MHRA warnings, are worth weighing too. None of this is a substitute for individual advice, so if you are trying for a baby and taking finasteride, speak to your GP or a fertility specialist.
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