Fluctuations in your libido are expected, especially as you get older.

While lifestyle, medications, and stress can affect your sex drive, physiology can also be a factor. Testosterone, the hormone that boosts sexual desire, sperm production, bone density, and muscle mass, could be the culprit (1, 2, 3, 4, 5).

You might experience less interest in sex as the level declines, or you might not perform as well as you’d like sexually. A dip in sexual desire can cause depression and could affect intimate relationships. It’s natural to want to do something about it (6).

If you’re considering testosterone therapy to help improve your sex drive, here’s a look at the research.

Testosterone and estrogen are your primary sex hormones. Both men and women produce testosterone, but men make more. Alternately, a woman’s body creates more estrogen than a man’s (7).

Testosterone increases as a boy matures. It’s responsible for:

  • the maturity of sex organs
  • increased body and facial hair
  • bigger muscles
  • deeper voices

It also promotes sperm production.

Testosterone levels vary throughout the day, usually peaking early in the morning. Additionally, levels fluctuate over your lifespan and decline every 10 years, usually 1–2 percent per year after age 30 (8, 9, 10).

This could mean you have less interest in sex later in life and possibly fewer firm erections, as well as softer muscle tone.

Aside from aging, there are several other causes that can result in lowered testosterone. They include:

Hypogonadism is a condition that occurs when the body does not produce enough testosterone on its own. Testosterone replacement therapy is usually used to treat hypogonadism. However, it’s unclear whether supplements can help.

The Endocrine Society recommends offering testosterone therapy to people with symptoms of testosterone deficiency. In men over 65 years old, treatment should only be initiated on an individual basis and after consultation with the person regarding risks and benefits. (11).

Furthermore, an analysis of 156 controlled trials between 1950 and 2016 where participants were given supplements didn’t find benefits for sexual, physical, and cognitive function, mood, or cardiovascular health.

But since the study also includes individuals without hypogonadism, the results may offer an unclear picture (12).

In fact, testosterone supplements might cause more problems than they solve. Studies have suggested a connection between supplements and heart problems. One study found that some men over age 65 had increased heart problems when they used testosterone gel (13, 14, 15).

Another study involving a group of men under age 65 who had a history of heart problems and a group of heart-healthy older men showed that both groups had a greater risk of heart attacks when taking testosterone supplements (16).

Furthermore, while there are contradictory findings, the use of testosterone replacement therapy may increase your risk of prostate cancer and cardiac issues (17, 18, 19).

Like other supplements and medications, testosterone therapy comes with risks and possible side effects. This is particularly true if you try to take it for normal aging rather than to treat a condition.

The effects that these supplements may have on your heart and prostate can lead to some potential issues. Complications can include:

While low testosterone is a common cause of low sex drive in men, there are various other possible causes.

Psychological causes can contribute to low libido. These include:

In addition to low testosterone, various other physical causes can result in a decreased sex drive. Some of these reasons include:

Your healthcare professional can help you determine what’s causing your low libido. And they may recommend counseling if they believe psychological factors are contributing to it.

Testosterone therapy is not right for everyone. There are also natural remedies available that you can try:

  • Get enough zinc. One study found zinc to be essential in helping regulate serum testosterone levels in men. You can add zinc to your diet by eating whole grains and shellfish, or through supplementation.
  • Eat potassium-rich foods. Potassium aids in testosterone synthesis. Add potassium-rich foods like bananas, beets, and spinach to your meals.
  • Exercise regularly. Exercise has been shown to naturally increase testosterone, but various factors affect which types of exercise are helpful and to what extent testosterone levels are impacted.
  • Reduce the amount of sugar you consume. Research has shown that sugar can reduce testosterone levels.
  • Get more sleep. Older research from a small study showed that sleep deprivation resulted in decreased testosterone levels.
  • Reduce your stress levels. One way to do that is learning and practicing stress management techniques.

Before starting any natural remedies, or making any other changes to your treatment plan, talk with your healthcare professional.

Are testosterone supplements safe for everyone?

No. While they may be helpful for those with hypogonadism, they should not be used by people who have:

  • normal testosterone levels
  • prostate cancer or are at increased risk of prostate cancer
  • a history of heart problems

It’s important to talk with your doctor about the potential risks and benefits before taking testosterone supplements.

How long does it take to see results from testosterone supplements?

A 2011 research review of testosterone supplementation in men with hypogonadism found that it took between 3 weeks and 6 months to see results in various areas (20).

What else can you do to increase testosterone levels?

If testosterone supplements aren’t right for you, you can increase testosterone levels naturally by:

  • getting more sleep and exercise
  • reducing sugar intake
  • lowering stress levels
  • adding more zinc and potassium to your diet

There can be many reasons for a drop in your sex drive. Decreasing testosterone levels could be the source but so could life stresses or relationship problems.

Testosterone supplements can boost sex drive for some, but ask your healthcare professional for testosterone testing to determine whether supplementation is the best option for you, as they have been linked to prostate cancer and cardiovascular issues.