Some medications and all illegal drugs come with ill effects on a man’s fertility. If you are trying for a child, make sure that you talk to your doctor about its side effects before consuming them. Illegal drugs should be avoided at any cost as they affect not just fertility but also general well-being.

• Testosterone
  Testosterone replacement can have a harmful effect on the production of sperms. When testosterone is taken externally, the testicles no longer produce their testosterone and hence, the production of sperms is stopped. The outcome is that the semen analysis will show low sperm count or no sperms at all. The effects can be reversed by stopping the use of the drugs. But it may take 6 to 12 months to regain the normal sperm production levels.
• Anabolic steroids
  These are used to decrease body fat levels or build muscle mass. The drugs are
  increasingly used in competitive athletes and non-athletic people alike. It affects male fertility negatively and also comes with other health concerns. The effects on fertility are similar to that of testosterone. Fortunately, the ill-effects can be reversed in 3 to12 months after the cessation of use.
• Alcohol
  Mild to moderate amounts of alcohol does not affect fertility in males but heavy
  drinking does. More than 10 to 14 drinks a week can reduce testosterone production and increase the oestrogen levels in the bloodstream. This can reduce the number of sperms or damage them too.
• Tobacco
  Tobacco and smoking is attributed to many major diseases. It can also affect male fertility. Studies have found that the chances of damaged sperms are more in smokers than in non-smokers. The sperm production and motility are also adversely affected.
• Marijuana
  Marijuana weakens sexual drive and reduces sperm production because of the THC, which is an active ingredient. It also directly affects the motility of the sperms. Heavy metals, sometimes found in it can also adversely affect male fertility.
• Narcotics
  Narcotics or opiates are prescribed by medical practitioners and are also used as illegal street drug. Its long-term use can cause low testosterone and reduce both the quantity and quality of the sperm. Men using opiates to counteract addiction must talk to their councillors to know how to cut back on them.
• 5-Alpha-reductase inhibitors
  These medications are prescribed to treat hair fall and prostate enlargement. They can cause reduced semen volume and decreased sperm count. The effects are mild and can be reversed after the cessation of use.
• Alpha-blockers
  These drugs are commonly used to treat the urinary symptoms of enlarged prostate.These medications can cause reduced semen on ejaculation or can stop ejaculation altogether. IF you take these, talk to your doctor about alternative options for treatment.
• Selective serotonin reuptake inhibitors
  These drugs are commonly administered for the treatment of anxiety and depression. These are known to cause sexual dysfunction and a long time to ejaculation.
• Ketoconazole
  Ketoconazole is a common drug prescribed to treat infections of fungal origin. It can be used as a cream, powder or ointment safely. But when taken as a pill internally, it can decrease sperm production by interfering with testosterone.
• Chemotherapy
  Chemotherapy is used to treat cancer and can interfere with sperm production. The production of sperm can go back to its normal form in two years after the treatment. It can also cause the man to become infertile depending on the kind of chemotherapy administered. If you are to undergo chemotherapy and wish to have a child in the future, talk to your doctor about preserving your sperm before the treatment commences.
• Other drugs
  Other medications that can affect male fertility are spironolactone, nifedipine, cimetidine, sulfasalazine, colchicine and some antibiotics.