Chemotherapy uses anti-cancer (cytotoxic) drugs to destroy cancer cells. Some of the side effects of chemotherapy, such as feeling sick, weakness, depression, tiredness and lack of energy, can reduce your sex drive. However, these side effects of treatment can often be reduced or stopped with medicines.

Once chemotherapy is over, your sex drive will usually come back in time. Unfortunately, if the chemotherapy has made your hair fall out, or if you have lost weight, or if you have a central line or PICC line you may feel very unsexy. Some of the tablets given to prevent sickness cause a low sex drive. Once you stop taking these tablets your sex drive should return.

In women, chemotherapy can reduce the amount of hormones produced by the ovaries. You may notice changes in your monthly periods, which can sometimes stop altogether. Despite this change, it is important to talk to your doctor about contraception because it is still possible to become pregnant even with irregular menstrual cycles.

You should use a reliable barrier method of contraception all through your treatment and for up to a year afterwards.

Tiredness

Tiredness and the change in hormone levels may also cause a lower sex drive, and to reduced arousal during sex. Some medicines can help to increase sexual drive and improve arousal. You can discuss this with your doctors.

Symptoms of early menopause

Because chemotherapy can reduce the amount of hormones produced by the ovaries, it can cause the symptoms of an early menopause, including hot flushes, irritability, sleep disturbances and vaginal dryness. Vaginal thrush is common in women having chemotherapy, especially if you are taking steroids or powerful antibiotics to prevent infection. Your doctor can prescribe treatment for this.

Some men find that their sex drive falls at the time of the therapy, due to tiredness and possibly feelings of sickness. It will usually return to normal soon after the end of the therapy. Some types of therapy reduce the amount of male hormone (testosterone) that is produced, but this also usually goes back to normal in time.

Pregnancy

If you are pregnant before your cancer is diagnosed and your chemotherapy starts, it is very important to discuss with your doctor the pros and cons of continuing with your pregnancy. It is sometimes possible to delay starting chemotherapy until after the baby is born. It depends on the type of cancer you have, the extent of the cancer, how advanced the pregnancy is and the particular chemotherapy you will be having.

You should talk to your doctor about your pregnancy and be sure that you are fully aware of all the risks and alternatives before making any decisions. You can also talk to our nurses at Cancerbackup.

Contraception during chemotherapy

Although chemotherapy can reduce fertility, it is quite possible for a woman having chemotherapy to become pregnant during the treatment. The side effects of chemotherapy, such as sickness and diarrhoea, can make the contraceptive pill less effective. Female partners of a man having chemotherapy can also become pregnant.

Pregnancy should be avoided during chemotherapy (in both men and women) in case the drugs harm the baby. For this reason, your doctor will advise you to use a reliable method of contraception (usually barrier methods of contraception - such as condoms or the cap) throughout your treatment and for up to a year afterwards.

Unfortunately some chemotherapy treatments may cause infertility in both men or women. Infertility is the inability to become pregnant or father a child. This may be temporary or permanent, depending on the drugs that you are having. It is very important that you fully discuss the risk of infertility with your doctor before you start treatment. If you have a partner, they will probably want to join you at this discussion so you can both be aware of all the facts. You will then both be able to talk over your feelings and options for the future.

Women and infertility

Some drugs will have no effect on your fertility, but some may stop your ovaries producing eggs, either temporarily or permanently. If this happens, it means, unfortunately, that you can no longer become pregnant and it will also bring on symptoms of the change of life (the menopause). During chemotherapy, your monthly periods may become irregular or stop and you may have hot flushes, dry skin and dryness of the vagina.

If your ovaries are going to start producing eggs again and the infertility is short-term, your periods will go back to normal after your treatment finishes. This happens in about a third of women. Usually, the younger you are, the more likely you are to get back to normal periods and still be able to have children after chemotherapy.

Depending on the type of cancer you have, your doctor can often prescribe hormone replacement therapy (HRT) to help relieve the menopausal side effects. Unfortunately, the hormones will not make you start producing eggs again and so can’t prevent infertility.

Men and infertility

Some chemotherapy drugs will have no effect at all on your fertility, but some may reduce the number of sperm you produce or affect their ability to reach and fertilise a woman’s egg during sex. Unfortunately, this means you may no longer be able to father children. However, you will still be able to get an erection and have an orgasm as you did before you started your treatment.

If the chemotherapy causes infertility, some men will remain infertile after their treatment has stopped, while some find their sperm goes back to normal levels and their fertility comes back. Sometimes it may take a few years for fertility to return. Your doctor will be able to do a sperm count to check your fertility when your treatment is over.

See our sections on the options for dealing with infertility and fertility and cancer.