Male Reproductive Hormones 101

When it comes to your fertility, hormones are the stars of the show. But for many of us guys, we know little to nothing about the hormones involved in reproduction – or what their levels mean for our fertility. Here we’ll lay out some of the key players when it comes to male sex hormones and explain what role each of them plays in the baby-making process – as well as for our overall health.

Testosterone

If there’s one male sex hormone you’re probably familiar with – it’s testosterone. This hormone is what really kick-starts the process of fertility and impacts many areas and functions of the body including:

• Your bone mass
• The amount of body fat and muscle mass you have
• Your sex drive
• And your sperm production and fertility

Testosterone is produced in the testicles and production is triggered by Luteinizing Hormone (but more on that later). Our T levels naturally rise through puberty, peaking in our early 20s and then slowly declining with age. However, for a healthy adult male, levels should be between 300 and 1,000 nanograms (ng) per deciliter (dL) or ng/dL.

What does it mean if I have low testosterone?

If your testosterone levels are measured below 300 nd/dL you could be classed as having Low T – also known as hypogonadism. There are lots of reasons that your testosterone could be running low – from aging to diet, and medical treatment to genetic conditions.

Some of the signs and symptoms of Low T include

• Erectile dysfunction
• Low sex drive
• High body fat and low muscles mass
• Low mood

Whilst low testosterone doesn’t always mean you will have trouble conceiving, if you have been trying for a while with no success, it’s worth getting checked out. If you want to know more about the signs and symptoms of low T – we wrote a whole blog article about it!

What does it mean if I have high testosterone?

Cases of naturally too-high testosterone are fairly rare, but they can be a sign of a tumour on the testicles or Cushing syndrome.

However, taking steroids or other forms of synthetic testosterone can increase your levels to a worrying degree. It’s easy to think that high testosterone = high fertility, but the truth is that messing with your hormones with things like steroids can throw your hormonal balance off and cause issues with sperm production.

You can learn more about the impact of steroids on male fertility hormones here.

Follicle-stimulating hormone (FSH)

Follicle-stimulating hormone (FSH) is produced in the pituitary gland, and the gland is triggered to release FSH from an area of your brain called the hypothalamus. FSH is talked about a lot in female fertility, but it’s also important for guys too, as it plays a key role in sperm production.

What does it mean if I have low FSH?

Normal FSH levels for a healthy, adult man are between 1.5 and 12.4 mIU/mL. If your levels are lower than this, it could indicate that something isn’t working properly in either your pituitary gland or hypothalamus. Low FSH has been linked to various male fertility issues including low sperm count and low sperm quality.

What does it mean if I have high FSH?

If your FSH levels are abnormally high – this could indicate a few things. Overall it means FSH isn’t having the proper effect on your testicles, which could impair sperm production just as much as low FSH. High FSH could indicate that your sexual development has been impacted by conditions such as Klinefelter syndrome, or it could also be connected to treatments like chemotherapy.

Luteinizing Hormone (LH)

Another important sex hormone is luteinizing hormone (LH). Like FSH, it’s produced in the pituitary gland and is heavily involved in the process of reproduction. As we mentioned earlier, LH triggers the testicles to produce testosterone, so if your LH levels are off, it could have a knock-on effect on your testosterone levels too!

What does it mean if I have low LH?

Normal LH levels for healthy adult men are between 1.8 and 8.6 IU/L. If your LH is lower than that, similarly to FSH, it could indicate a pituitary gland or hypothalamus disorder. If you don’t address low LH levels, it could cause low T and potential issues with sperm production and fertility.

What does it mean if I have low LH?

Again, low LH levels have very similar connotations as low FSH – it could be connected to radiotherapy, infection, or even Klinefelter Syndrome. Some studies indicate that increased levels of LH could be connected to low sperm motility and morphology.

Thyroid-Stimulating Hormone (TSH)

The role of Thyroid-stimulating hormone (TSH) is to tell the thyroid to produce thyroid hormones. Thyroid hormones impact many essential functions in your body – including reproduction. Normal TSH levels for guys are between 0.4 and 5.49 mIU/L – but this can vary with age.

What does it mean if I have low TSH?

If you already have high levels of thyroid hormone in your body, the pituitary gland will reduce the amount of TSH produced – this is known as hyperthyroidism. This condition can cause weight loss, fatigue, feelings of weakness or anxiety and even make you go to the toilet more often. It’s also been linked to low sperm volume, low sperm concentration and poor motility and morphology.

What does it mean if I have high TSH?

However, if your thyroid hormone levels are running low, the body will produce more TSH and your levels can become high – this is known as hypothyroidism. This condition can trigger weight gain, hair thinning, fatigue and constipation – it’s also been linked to poor sperm morphology.

Estrogen

Estrogen? I thought that was a female sex hormone. Well, you’re right – but just as women need testosterone to function healthily, men need some estrogen. In men, estrogen helps to support muscle mass, cholesterol levels, blood sugar levels – and fertility.

What does it mean if I have low estrogen?

Some estrogen is produced directly in the testicles, whilst the rest occurs when the skin, bones and brain convert testosterone into estrogen. That means that very often the cause of low estrogen can be low testosterone – and therefore the symptoms and impact on fertility can be very similar.

What does it mean if I have high estrogen?

High levels of estrogen can be triggered by various factors including stress, liver conditions or being overweight. If your estrogen is overly high it could impact your sexual function (it’s been linked to erectile dysfunction), cause you to have enlarged breasts and could even lead to prostate cancer.

Prolactin

Another hormone you might associate with females is Prolactin – the hormone heavily involved in breastfeeding. However, for men it supports the effect of LH in the testicles which helps with testosterone production. Like FSH and LH, it’s produced in your friend and mine – the pituitary gland and is affected by dopamine and estrogen.

What does it mean if I have low prolactin?

Levels of prolactin males are generally pretty low – less than 20 ng/mL. There’s technically no worryingly low level of prolactin in a healthy adult male, so there aren’t really any concerns or symptoms to be aware of!

What does it mean if I have high prolactin?

However, overly high levels of prolactin can be a cause for concern – around 11% of infertile men test high when it comes to this hormone.

Some symptoms of high prolactin include erectile dysfunction, reduced sperm production and even a milky secretion from the nipples. High prolactin can be caused by certain medications, issues with the pituitary gland and also kidney disease.

Should I get my male hormones tested?

When it comes to reproduction, hormones are a delicate balancing act, and if any of the above hormones are out of line, it can have a knock on effect on your fertility. However, the main ones to be concerned with are testosterone, FSH and LH.

However, unless you have any direct symptoms that are causing you concern, there’s no rush to get your hormones tested. First we’d recommend testing your sperm to get a good idea of your fertility. If you find that your sperm health is sub-optimal, then it might be worth analysing your levels of male reproductive hormones to see if they could be the root cause of your fertility problems.

Our at home sperm test makes it quick and easy to get to know your swimmers – you can learn more about our test kits here.