Infertility is a growing problem worldwide.
While infertility is not always treatable, it can sometimes be improved with a healthy diet, supplements and other lifestyle strategies.
This article lists some of the main lifestyle factors, foods, nutrients and supplements that have been associated with improved fertility in men.
Fertility refers to people's ability to reproduce by natural means.
Male infertility is when a man has a poor chance of making his female partner pregnant. It usually depends on the quality of his sperm cells.
The following aspects of sexual function and semen quality may affect fertility:
- Libido: Otherwise known as sex drive, libido describes a person's desire to have sex. Foods or supplements that claim to increase libido are called aphrodisiacs.
- Erectile dysfunction: Also known as impotence, erectile dysfunction is when a man is unable to develop or maintain an erection.
- Sperm count: An important aspect of semen quality is the number or concentration of sperm cells in a given amount of semen.
- Sperm motility: An essential function of healthy sperm cells is their ability to swim. Sperm motility is measured as the percentage of moving sperm cells in a sample of semen.
- Testosterone levels: Low levels of testosterone, the male sex hormone, may be responsible for infertility in some men.
Infertility can have multiple causes and may depend on genetics, general health, fitness, diseases and dietary contaminants.
Additionally, a healthy lifestyle and diet are important. Some foods and nutrients are associated with greater fertility benefits than others.
Here are 10 science-backed ways to boost sperm count and increase fertility in men.
D-aspartic acid (D-AA) is a form of aspartic acid, a type of amino acid that's sold as a dietary supplement.
It should not be confused with L-aspartic acid, which makes up the structure of many proteins and is far more common than D-AA.
D-AA is mainly present in certain glands, such as the testicles, as well as in semen and sperm cells.
Researchers believe that D-AA is implicated in male fertility. In fact, D-AA levels are significantly lower in infertile men than fertile men (3).
This is supported by studies showing that D-AA supplements may increase levels of testosterone, the male sex hormone that plays an essential role in male fertility.
For instance, an observational study in infertile men suggested that taking 2.66 grams of D-AA for three months increased their testosterone levels by 30–60% and sperm count and motility by 60–100%.
The number of pregnancies also increased among their partners (4).
However, the evidence is not entirely consistent. Studies in athletes or strength-trained men with normal to high testosterone levels found that D-AA didn't increase its levels further and even reduced them at high doses (6, 7).
Taken together, the current evidence indicates that D-AA supplements may improve fertility in men with low testosterone levels, while they don't consistently provide additional benefits in men with normal to high levels.
Further studies need to investigate the potential long-term risks and benefits of D-AA supplements in humans.
Summary: D-aspartic acid (D-AA) supplements may improve testosterone levels and fertility in infertile men or those with low testosterone levels. However, scientists haven't reached a definite conclusion at this point.
Exercising not only improves your confidence and physical performance — it may also raise your testosterone levels.
If you rarely exercise but want to improve your fertility, becoming more physically active should be one of your top priorities.
Summary: Exercising regularly can boost your testosterone levels and improve your fertility.
Oxidative stress is when levels of reactive oxygen species (ROS) reach harmful levels in the body.
ROS are constantly being produced in the body, but their levels are kept in check in healthy people. High levels of ROS may promote tissue injury and inflammation, increasing the risk of chronic disease (17).
Adequate intake of antioxidants, such as vitamin C, may help counteract some of these harmful effects. There is also some evidence that vitamin C supplements may improve semen quality.
A study in infertile men showed that taking 1,000-mg vitamin C supplements twice a day for up to two months increased sperm motility by 92% and sperm count by more than 100%. It also reduced the proportion of deformed sperm cells by 55% (20).
Another observational study in Indian industrial workers suggested that taking 1,000 mg of vitamin C five times a week for three months may protect against DNA damage caused by ROS in sperm cells.
Vitamin C supplements also significantly improved sperm count and motility, while reducing the numbers of deformed sperm cells (21).
Taken together, these findings suggest that vitamin C may help improve fertility in infertile men suffering from oxidative stress.
However, controlled studies are needed before any definite claims can be made.
Summary: Oxidative stress may lead to infertility in men. Some evidence indicates that taking antioxidant supplements, such as vitamin C, may improve fertility.
Researchers believe the hormone cortisol may partly explain these adverse effects of stress.
While severe, unexplained anxiety is typically treated with medication, milder forms of stress can be alleviated by numerous relaxation techniques.
Stress management can be as simple as taking a walk in nature, meditating, exercising or spending time with friends.
Summary: Stress can reduce sexual satisfaction and fertility. Stress management and relaxation should be high on your agenda.
Vitamin D is another nutrient that may boost your testosterone levels.
One observational study showed that vitamin D-deficient men were more likely to have low testosterone levels (27).
A controlled study in 65 men with low testosterone levels and vitamin D deficiency supported these findings. Taking 3,000 IU of vitamin D3 every day for one year increased their testosterone levels by around 25% (28).
Summary: Taking vitamin D supplements may boost testosterone levels in vitamin D-deficient men with low testosterone levels.
Tribulus terrestris, also known as puncturevine, is a medicinal herb frequently used to enhance male fertility.
One study in men with low sperm counts showed that taking 6 grams of tribulus root daily for two months improved erectile function and libido (31).
However, further studies need to confirm its aphrodisiac properties and evaluate the long-term risks and benefits of supplementing with it.
Summary: One study suggests that Tribulus terrestris may enhance libido and erectile function in men, but the current evidence is weak.
Fenugreek (Trigonella foenum-graecum) is a popular culinary and medicinal herb.
One study in 30 men who strength-trained four times a week analyzed the effects of taking 500 mg of fenugreek extract daily.
The men experienced significantly increased testosterone levels, strength and fat loss, compared to a placebo (35).
Another study in 60 healthy men showed that taking 600 mg of Testofen, a supplement made from fenugreek seed extract and minerals, daily for six weeks improved libido, sexual performance and strength (36).
These findings were confirmed by another, larger study in 120 healthy men. Taking 600 mg of Testofen every day for three months improved self-reported erectile function and the frequency of sexual activity.
Also, the supplement significantly increased testosterone levels (37).
Keep in mind that all of these studies examined fenugreek extracts. It is unlikely that whole fenugreek, which is used in cooking and herbal tea, is as effective.
Summary: A few studies examining the use of fenugreek to improve sexual performance and libido have shown promise. However, most studies used a fenugreek seed extract supplement.
Zinc is an essential mineral found in high amounts in animal foods, such as meat, fish, eggs and shellfish.
Adequate zinc intake appears to be one of the cornerstones of male fertility.
Observational studies show that low zinc status or deficiency is associated with low testosterone levels, poor sperm quality and an increased risk of male infertility (38).
Controlled trials need to confirm these observational findings.
Summary: Taking zinc supplements may increase testosterone levels and improve fertility in men with low zinc status or deficiency.
Ashwagandha (Withania somnifera) is a medicinal herb that has been used in India since ancient times.
Studies suggest that ashwagandha may improve male fertility by boosting testosterone levels.
One study in men with low sperm cell counts showed that taking 675 mg of ashwagandha root extract per day for three months significantly improved fertility.
Specifically, it increased sperm counts by 167%, semen volume by 53% and sperm motility by 57%, compared to the start of the study. In comparison, minimal improvements were detected among those who got a placebo treatment (42).
Increased testosterone levels may be partly responsible for these benefits.
A study in 57 young men following a strength-training program showed that consuming 600 mg of ashwagandha root extract daily significantly increased testosterone levels, muscle mass and strength, compared to a placebo (43).
Summary: Ashwagandha is a medicinal herb that may increase testosterone levels and improve male fertility.
Maca root is a popular plant food that originated from central Peru. Traditionally, it has been used for its ability to enhance libido and fertility.
Studies also suggest that maca root may improve sexual performance. In men with mild erectile dysfunction, 2.4 grams of dried maca root slightly improved self-reported erectile function and sexual well-being (49).
Taking 1.75 grams of maca root powder every day for three months also increased sperm counts and motility in healthy men (50).
Additionally, maca root doesn't seem to affect hormone levels. Taking 1.5–3 grams of maca root per day for three months had no effects on testosterone or other reproductive hormones in healthy, fertile men (53).
Summary: Taking maca root supplements may improve libido, as well as fertility and sexual performance.
Numerous strategies may help improve your fertility, although this depends on its cause.
Also, keep in mind that fertility and libido usually go hand in hand with your general health.
For this reason, anything that improves your overall health is likely to boost your fertility at the same time.
Here are 8 additional tips to boost fertility and sperm count/quality:
- Lead a healthy lifestyle: Unhealthy lifestyle practices impair your overall health, including fertility (54).
- Lose excess weight: Obesity is associated with infertility. If you are infertile and obese, weight loss should be one of your top goals (55, 56, 57).
- Limit your alcohol intake: Avoid heavy alcohol consumption, as it may reduce testosterone levels and impair semen quality (58, 59).
- Get enough folate: A few studies indicate that a low intake of folate may impair semen quality (60, 61).
- Get adequate sleep: Getting adequate sleep is vital to maintaining your health. Restricted or excessive sleep has also been linked to poor semen quality (62).
- Snack on walnuts: Eating a lot of antioxidant-rich foods, such as walnuts, seems to benefit fertility (63).
- Consider supplements: Antioxidant supplements also seem to work. Some evidence suggests that coenzyme Q10 improves semen quality (64, 65).
- Avoid eating too much soy: Soy is rich in isoflavones, which are associated with lower semen quality (66).
Summary: If you are infertile, the lifestyle improvements or supplements above might benefit you. However, the evidence for most of these is weak and more research is needed.
Infertility affects many men around the world.
If you are one of them, focus first on improving your general health. Many of the tips mentioned in this article are key components of a healthy lifestyle.
None of them are guaranteed to work, but if you suffer from nutrient deficiencies or low testosterone levels, chances are that they may help.