In short: Sperm health depends on how many sperm are produced, how well they move and their shape. It can be affected by smoking, heavy drinking, recreational drugs, anabolic steroids or testosterone use, excess weight, heat around the testicles, some medicines and medical conditions, and age. Because sperm take around three months to develop, healthy changes take a few months to show. If you have been trying for a baby for a year without success (or sooner if your partner is 36 or over, or there is a known problem), both partners should be assessed.

This guide, written by a Ready Health prescribing pharmacist, explains what affects male fertility, practical steps that can help, and when to seek tests and advice.

What makes sperm healthy?

A semen analysis looks at several features, which are compared with reference values published by the World Health Organization:

Sperm concentration and count: how many sperm are in the sample.
Motility: the proportion of sperm that move, and how well they swim forwards.
Morphology: the proportion with a normal shape.
Volume and other features of the semen.

Results below the reference range do not mean you cannot father a child, and results within it do not guarantee fertility. Sperm quality also varies naturally from one sample to the next, so an abnormal result is usually repeated.

What can affect sperm health?

Lifestyle factors

Smoking is linked with poorer sperm quality.
Alcohol: drinking more than the UK low-risk guideline of 14 units a week, spread across several days, can affect sperm.
Recreational drugs such as cannabis and cocaine can harm sperm production and function.
Anabolic steroids and testosterone (including products bought online or in gyms) can severely reduce or stop sperm production. Recovery can take many months and is not always complete.
Weight: a body mass index of 30 or over is associated with reduced fertility.
Heat: the testicles work best slightly below body temperature. Tight underwear, long hot baths or saunas, and resting a laptop on your lap for long periods may affect sperm.

Medical causes

a varicocele (enlarged veins in the scrotum)
a history of undescended testicles, testicular injury, surgery or mumps affecting the testicles
sexually transmitted or other genital infections
hormone problems, for example affecting the pituitary gland
some genetic conditions
diabetes, and problems with erection or ejaculation
cancer treatment such as chemotherapy or radiotherapy
some medicines, which a clinician should review before you stop anything

Age

Men produce sperm throughout life, but sperm quality and fertility gradually decline with age, and the time it takes to conceive tends to be longer when the male partner is older.

How can I improve my sperm health?

Stop smoking and avoid recreational drugs.
Keep alcohol within 14 units a week.
Do not use anabolic steroids or unprescribed testosterone. If you take prescribed testosterone and want children, speak to your prescriber before trying to conceive.
Aim for a healthy weight with regular physical activity.
Eat a balanced diet with plenty of fruit, vegetables and wholegrains.
Wear loose-fitting underwear and avoid prolonged heat to the groin.
Look after your sexual health and use condoms with new partners.
Have regular sex, every two to three days, when trying to conceive rather than timing it only around ovulation.
Manage stress and get enough sleep.

Many fertility supplements are marketed for men, but the evidence that they improve the chance of pregnancy is limited. Speak to a pharmacist or doctor before taking them, particularly if you take other medicines.

When should a man get a fertility check?

NHS advice is to see a GP if you and your partner have been trying to get pregnant for a year without success. Seek advice sooner if:

your partner is 36 or older
you have a history of testicular problems, surgery, cancer treatment or a known condition affecting fertility
you have problems with erections or ejaculation
you have used anabolic steroids or testosterone

See a GP promptly if you notice a lump, swelling or persistent pain in a testicle, whether or not you are trying for a baby.

What happens during male fertility testing?

Medical history and examination, including medicines, lifestyle and sexual health.
Semen analysis: usually a sample produced after 2 to 7 days without ejaculation, delivered to the laboratory within a set time. If the result is abnormal, it is usually repeated, ideally around three months later.
Blood tests such as hormone levels (for example testosterone, FSH and LH) where a clinician thinks they are needed.
Further tests, such as screening for infections, an ultrasound scan or genetic tests, depending on the findings.

Treatment depends on the cause. It may include treating an infection or hormone problem, surgery in some cases, or assisted conception such as IVF or ICSI. NHS funding criteria for fertility treatment vary by area.

Men's health and fertility advice in Wigan and Standish

Ready Health in Standish, near Wigan, offers men's health appointments and private blood tests, including hormone checks. A clinician can talk through your concerns, review lifestyle factors and medicines, arrange relevant tests and explain your results, and will advise when referral through your NHS GP or a fertility service is the right next step.

Frequently asked questions

How long does it take to improve sperm quality?

Sperm take around three months to develop, so lifestyle changes usually need about three months before any effect shows in a semen sample.

Does testosterone treatment affect fertility?

Yes. Testosterone and anabolic steroids switch off the signals that tell the testicles to make sperm, which can greatly reduce sperm count. Anyone planning a family should discuss this with a prescriber.

Can a blood test check male fertility?

A semen analysis is the main test of male fertility. Blood tests for hormones such as testosterone, FSH and LH can help find a cause if the semen analysis is abnormal or symptoms suggest a hormone problem.

Do laptops and phones affect sperm?

Heat from a laptop resting on your lap for long periods may affect sperm. Evidence about mobile phones is less clear. Keeping the groin cool is a simple precaution.

Key takeaways

Sperm count, movement and shape are assessed by semen analysis.
Smoking, alcohol, drugs, excess weight, heat and steroid or testosterone use can all reduce sperm quality.
Lifestyle changes take about three months to affect sperm.
See a GP after a year of trying, or sooner if your partner is 36 or older or you have known risk factors.
Both partners should be assessed when a couple is having difficulty conceiving.

Sources and further reading

Last reviewed: October 2026 by Shamir Patel, Independent Prescribing Pharmacist, Ready Health. This article is general information and does not replace advice from your own clinician.

If you have concerns about your fertility or male hormones, book a men's health appointment at Ready Health in Standish to discuss tests and next steps with a clinician.

Male Fertility: What Affects Sperm Health and How to Improve It