Certain drugs (legal and illegal) can have a negative effect on male fertility (a man’s ability to father a child). Listed below are the most common substances that affect male fertility. Men who wish to father a child should talk to their doctor before starting a new medication or having any treatments.
Men who are having trouble fathering a child should speak to their doctor about the medications they are taking, and the possible need for semen tests. Some men may have an unexpected side effect from a medication that can harm their fertility. If your doctor thinks that this may be the case, it may be a good idea to stop the medication or try a different one. You should always discuss this decision with the doctor who prescribed the medication.
Drugs that may affect male fertility
- Testosterone: Replacement testosterone (also called supplemental testosterone) has a strong negative effect on sperm production. When testosterone is given to a man, the hormonal signals that tell the testicles to make testosterone and to make sperm are blocked, and the man’s natural testosterone production stops. This causes the level of testosterone in the testicles to drop sharply–too low to support strong sperm production. The most likely outcomes are a very low sperm concentration or a complete absence of sperm from the semen.
This effect can be reversed for most men; however, it may take 6 months or more for sperm production to return to normal. In general, men who are trying to cause a pregnancy should not use supplemental testosterone.
- Anabolic steroids: Anabolic steroids (also called anabolic-androgenic steroids) are drugs that are used to build muscle mass and/or decrease body fat. Testosterone is an anabolic steroid. The use of these drugs is increasing among non-competitive athletes and non-athletes. Unfortunately, fitness and muscle-building dietary supplements from less reputable sources may be tainted with anabolic steroids.
Anabolic steroids harm male fertility the same way that testosterone does: by interfering with the hormone signals that are needed to produce sperm. Just how much damage is done depends on the drugs(s), dose(s), and how long the man takes them. Most men will recover sperm production 3 to 12 months after they stop taking the drug.
Because of the strong negative impact of anabolic steroids on male fertility and the other health concerns related to these substances, men should not use these drugs.
- Alcohol: Light to moderate alcohol drinking does not appear to affect male fertility. Heavy alcohol drinking, however, may decrease the production of testosterone, increase the rate at which testosterone is cleared from the bloodstream, and increase a man’s estrogen levels. All of this can cause a lower testosterone level, which can harm sperm production.
Men who drink four or more alcoholic beverages on a regular basis should consider drinking less.
- Tobacco: Tobacco use in general, and smoking in particular, is linked to serious health conditions. Babies in households with people who smoke are much more likely to have serious respiratory illness such as severe asthma, pneumonia, and repeated ear infection. Sudden Infant Death Syndrome (SIDS) has also been linked to smokers in the household. And finally, children are more likely to smoke if their parents are smokers. The entire family can benefit when a family member stops smoking. For these reasons, couples who are trying to conceive should stop smoking.
- Marijuana: THC, the active ingredient in marijuana, decreases sperm production and weakens sexual drive by interfering with the production of testosterone. THC also has a direct harmful effect on the movement of sperm. Marijuana may also be laced with heavy metals (such as lead) to increase its weight or more addictive illicit drugs, such as cocaine.
Because of the negative effects of marijuana on male fertility, couples considering pregnancy should stop all marijuana use.
- Opiates (narcotics): Opiates include both prescription medications (for treating pain and addiction) and illegal street drugs. Long-term use of opiates can disrupt the signals that control testosterone production, which can cause low testosterone and decrease the quantity and quality of the sperm. The extent of the impact depends on the opiates being used, the dose, and how long the man is using the opiates.
Men taking opiates to treat addiction should speak with their addiction counselor about the impact of their medications on fertility, as some treatments are less harmful than others.
There is no evidence that the short-term use of opiates has a negative effect on male fertility. Therefore, men taking a short course of opiates, for instance to control pain after surgery or a broken bone, should take these medications according to the instructions. Men taking opiates for weeks or months should speak to their doctor about how to cut back on opiate use.
The recreational (illegal) use of any opiates is strongly discouraged.
- 5-alpha-reductase inhibitors (finasteride, dutaseride, and propecia): These medications are used to treat prostate enlargement and hair loss. The impact of these medications is mild and will reverse once the medication is stopped. Men who use these drugs to treat prostate enlargement will have a decrease in the volume of the semen and the total number of sperm in the semen, which may make it harder to create a pregnancy. Most men taking this medication to treat hair loss will not have a serious change in their sperm numbers. However, up to 5% of men taking this medication for either reason will have a major reduction in their sperm numbers. For that reason, we recommend men stop these medications if they are having trouble creating a pregnancy.
- Alpha blockers (Silodosin, Tamsulosin, Alfuzosin, Hytrin, Cardura): Alpha blockers are used to treat urinary symptoms caused by an enlarged prostate. These medications affect male fertility in different ways, depending on which way each medication works. Silodosin and Tamsulosin can both cause a sharp decrease in the volume of ejaculation or may inhibit ejaculation completely.
Men who are taking an alpha blocker or having urinary symptoms should see a urologist to discuss the possible impact of the alpha blockers on fertility, and the treatment options for urinary symptoms.
- PDE5 inhibitors (Viagra, Levitra, and Cialis): PDE5 inhibitors are used to treat erectile dysfunction. These medications do not appear to have a negative effect on male fertility.
- Selective serotonin reuptake inhibitors (SSRIs): These medications are commonly prescribed in the United States for the treatment of depression and anxiety. These medications may prevent the proper movement of sperm through the reproductive tract or otherwise harm the sperm.
Men who take SSRIs and who are having trouble fathering a child should see a urologist for semen testing, and talk with their mental health provider about other medications.
- Ketoconazole: This medication is used to treat fungal infections. It is commonly applied to the skin as a cream, ointment, or powder. There is no evidence to suggest that applying ketoconazole to the skin harms male fertility. When it is taken as a pill, ketoconazole hurts testosterone production and decreases sperm production.
- Other medications: The following medications may cause male fertility problems: spironolactone, cimetidine, nifedipine, sulfasalazine, and colchicine. If you are having trouble creating a pregnancy and are taking these medications, talk to your doctor and see a urologist for semen testing