Up to 80 percent of male infertility cases are related to oxidative stress. All those little daily assaults on the cells—both from normal wear and tear and toxins (tobacco, trauma, weight gain, etc.)—take their toll on the reproductive system along with the rest of the body. Antioxidants help prevent and repair this microdamage, like tiny garbage trucks picking up all the cellular trash. Based on this and the fact that supplements have improved fertility in clinical studies, I believe most male fertility experts should (and do) recommend supplements.
When my brother Andy, who’s in his forties, and his wife were trying to have a baby, all of his specialists encouraged using supplements (and they had a beautiful baby boy). Research shows that taking folic acid during pregnancy can help prevent neural tube defects, while other supplements help improve male fertility.
I think it’s interesting that even with as much criticism as some supplements get, conventional medicine clearly relies on dietary supplements for men and women when it comes to the perpetuation of our species. I know of no greater endorsement in all of medicine! Every day desperate couples pay ridiculous amounts of money for assisted reproductive techniques (ART). So it’s definitely worth working with your doctor to see if any of the cost-effective dietary supplements in this section can help, with or without ART.
What is Men Infertility?
Here’s a quick physiology review: Sperm cells (spermatozoa) travel within the seminal fluid, which is rich in nutrients; the combination of sperm and seminal fluid is known as semen. When something abnormally impacts sperm or seminal fluid production, male infertility (I also call it subfertility, although other doctors may have slightly different definitions) can occur. Conversely, any nutrients that can help facilitate this process can improve male fertility.
Infertility impacts about 15 percent of couples trying to conceive, and experts expect these numbers to increase dramatically because men and women are waiting longer than ever before to have a baby (plus, obesity has a huge negative impact on both male and female fertility).
Approximately half of infertility cases can be attributed to the male (women used to take the brunt of the blame, but once again, just like driving directions and remembering anniversaries and birthdays, the men got it wrong). Half of males undergoing evaluation for infertility have abnormal sperm measurements, and one of the most common findings is called oligoasthenoteratozoospermia (or simply, OAT).
Essentially, it’s a scary word for a trio of problems: low number of sperm, poor sperm movement, and abnormal sperm shape, and it can be traced back to oxidative stress. (Reduced sperm motility by itself is referred to as asthenozoospermia or asthenospermia.) Regardless, for many of the men diagnosed with infertility, there’s no obvious or contributory cause.
The largest research review ever completed on dietary supplements for male infertility involved men/couples undergoing ART. The researchers looked at pregnancy rates and live births and concluded that oral antioxidant supplements could improve the chances of conception during fertility treatment. They didn’t recommend specific supplements, though. Why not? So many different supplements help reduce oxidative stress and improve fertility that they weren’t able to single out any specific ones. I would argue, however, that if you look at benefit versus risk, there are some standouts (and some I would avoid).
What is the Best Supplement For Treating Men Infertility?
1. Multinutrient fertility supplement one or two pills a day, or simply one or two multivitamins per day
This is one of the only conditions in the book where taking two multivitamins or multinutrient fertility supplements a day makes some sense. You want to be replete with nutrients to help the fertility process. And since you’re generally only taking these for a short time—not years and years—the benefit outweighs the risk.
ProXeed (manufactured by Sigma-Tau) is popular with physicians because there’s some preliminary research showing men who take it have increased pregnancy rates with their partners. It contains several nutritional compounds that have also been shown to be beneficial for fertility (most are discussed in this section). It’s a little pricier to buy this versus just buying the individual ingredients, but there is good quality control and research supporting it.
ProXeed (according to one study) contains L-carnitine (145 milligrams), acetyl-L- carnitine (64 milligrams), fructose (250 milligrams), citric acid (50 milligrams), selenium (50 micrograms), coenzyme Q10 (20 milligrams), zinc (10 milligrams), ascorbic acid (90 milligrams), vitamin B12 (1.5 micrograms), and folic acid (200 micrograms).
It’s safe to take two of these ProXeed pills or a general male multivitamin (the multi will add even more key nutrients) daily. Right about now you might be wondering what the difference is between fertility supplements and a multivitamin. Not much, but some of these combination fertility supplements contain more of the specific nutrients that have been tested against infertility in past clinical trials (like carnitine, CoQ10, and selenium).
2. (tie) CoQ10 200 to 300 milligrams a day
This fat-soluble antioxidant improves energy production and reduces oxidative stress, and since the male reproductive tract is susceptible to oxidative stress, it makes sense that it could be beneficial. In addition, levels of CoQ10 in the seminal fluid correlate with sperm count and motility. In one study, men with idiopathic (no known reason) reduced sperm motility who took 200 milligrams of CoQ10 per day for 6 months saw increased motility. Another study of 212 infertile men taking 300 milligrams over 26 weeks found significant improvements in multiple parameters, including sperm density, motility, and acrosome reaction (the ability of sperm to meet the egg).
More research is needed on pregnancy and live birth rates with CoQ10, but this supplement (also known as ubiquinone) has an excellent overall safety profile. I recommend men take 200 to 300 milligrams per day to help preserve fertility (take it with a meal that has some fat in it). Be aware that it has the potential to reduce the impact of warfarin because it has vitamin K–like clotting properties, but it may actually increase blood thinning when used with other drugs (like clopidogrel), so talk with your doctor if you plan to take it with other drugs. It can be costly, though, so shop around.
2. (tie) Vitamin C (ascorbic acid) 500 to 1,000 milligrams a day
Seminal fluid is high in vitamin C, and there is a relationship between higher vitamin C levels in the fluid and a lower risk of male infertility and improved male sperm quality. In addition, smoking and environmental toxins can dramatically lower vitamin C levels and damage sperm cells. Smokers, ex- smokers, and people exposed to toxins (such as lead) seem to respond well to vitamin C in terms of improving their overall antioxidant status, especially vitamin C levels. Studies have shown that consuming 500 to 1,000 milligrams daily of vitamin C in combination with other common antioxidants improves fertility in men. It is unknown if taking vitamin C by itself is as beneficial as taking the combination supplements (see #1), but the upside outweighs the downside.
Taking more than 1,000 milligrams of C per day decreases absorption, increases side effects, and may be detrimental to fertility, so don’t overdo it. In fact, it could be argued that 500 milligrams per day improves fertility almost as well as 1,000 milligrams per day. A study by this super-smart guy named Moyad showed people at risk of kidney stones should choose buffered vitamin C or calcium ascorbate.
3. (tie) NAC (N-acetylcysteine) 600 milligrams a day
The liver produces a compound called glutathione, an antioxidant that’s found in very high concentrations in the body. Taking too much acetaminophen greatly reduces stores of glutathione, which leads to the formation of high concentrations of free radicals in liver cells, oxidative stress, liver injury, and in some cases failure (especially in combination with alcohol).
In the emergency room, doctors will give you NAC for an overdose of acetaminophen; it increases the production of glutathione to protect the liver from going into failure. Since glutathione is the primary anti-oxidant in the body, increasing levels of it protects against oxidative stress—and remember, up to 80 percent of male infertility cases are related to oxidative stress. You could just take glutathione supplements— and many people do—but they are poorly absorbed in the gastrointestinal tract. Instead, you’re better off taking NAC. One study showed taking 600 milligrams of NAC daily improved semen measurements, but more research is needed, especially for pregnancy and live birth rates. (NAC in combination with whey protein can boost glutathione levels as well.)
3. (tie) L-carnitine 2,000 to 3,000 milligrams a day
In every cell of your body, L-carnitine transports fatty acids from one area of the cell (cytosol) to another (mitochondria) as part of the energy production process.
Multiple clinical trials have demonstrated the ability of L-carnitine (or other forms of carnitine) to improve sperm characteristics and, potentially, pregnancy rates. Several randomized trials have found that L-carnitine improves sperm count, motility, and normal shape of sperm better than a placebo in men with idiopathic (no known cause) infertility.
Most trials have used an average of 2,000 to 3,000 milligrams per day (with or without food) or in the form of acetyl-L-carnitine without significant side effects. This is already a large dose and going beyond it can cause gastrointestinal problems, abnormal body odor, and neurologic concerns (such as peripheral neuropathy or nerve damage).
The reason I ranked it number three instead of at the top is that these dosages just aren’t practical for daily use. Plus, a few independent US studies from researchers I know and admire did not show the same dramatic results the previous studies did. There are several minimally different forms of L-carnitine, so take whichever you like (price does not connote effectiveness). There haven’t been enough studies yet to really identify adverse events or serious drug interactions with L-carnitine, so talk with your doctor.
4. Tongkat ali
Tongkat ali (Eurycoma longifolia), a plant that grows in the Malaysian rainforest, might improve various aspects of male health—including sex drive, testosterone levels (minimally, if at all), and sperm quality and quantity—as well as pregnancy rates, based on preliminary research using 200 milligrams a day. The product that has the most research—and the only one with real clinical data —is the standardized water-soluble extract of Eurycoma longifolia root called Physta (from Biotropics Malaysia).
The aqueous extract has multiple ingredients — including tannins, high-molecular-weight polysaccharides, glycoprotein mucopolysaccharides, and quassinoid alkaloids. It’s one of the only herbal products I would recommend for fertility because it has some research and a good safety profile.
What Supplements Are Useless For Treating Men Infertility?
Folic acid in large doses
This just isn’t an ideal antioxidant for male fertility. The Recommended Dietary Allowance is 400 micrograms a day, and it’s easy to get plenty of it from a bowl of cereal in the morning and a multivitamin.
Excessive folic acid (1 milligram or more) in men has been linked to a higher risk of prostate cancer. This finding is controversial (not definitive), but there’s just no need to take this risk when so many other supplements appear to work as well and are safer.
Selenium, vitamin E, and zinc
Large doses of selenium (200 micrograms or more) and vitamin E (400 IU or more) supplements should not be used to improve fertility in men. Selenium has a history of potentially increasing the risk of skin cancer recurrence at higher doses, and there may be a connection to an increased risk of type 2 diabetes as well.
With higher doses of vitamin E, there is a potentially elevated risk of all-cause mortality, heart failure, and even hemorrhagic stroke. (Breaking news: The largest trial of vitamin E and selenium found a significantly increased risk of prostate cancer in both groups upon further follow-up.) Zinc in large daily doses (80 to 100 milligrams or higher) has also been associated with higher rates of prostate cancer as well as hospitalizations for a variety of urologic conditions (the Recommended Dietary Allowance is only about 11 milligrams).
What Lifestyle Changes Can Men Infertility Help?
Heart healthy = sperm healthy
Most heart-unhealthy behaviors negatively impact almost all areas of male health, including fertility, therefore heart health is tantamount to male fertility.
Besides being heart unhealthy, obesity in men can increase estrogen levels, lower testosterone levels, and negatively impact fertility hormones. It can also reduce levels of a crucial compound involved in sperm support and production (inhibin B) and can increase testicular temperature, which can result in reduced sperm counts and motility and altered sperm shape.
Kick the habit
Smoking and tobacco use in general dramatically lowers sperm and seminal fluid nutrient levels and reduces the testicular production of sperm. Oh, and smoking can kill you in many other ways and cause chronic obstructive pulmonary disease, which dramatically reduces your ability to breathe.
In excess (more than a drink or two a day), alcohol can increase the risk of sperm damage in some people and alter hormone levels that may make it more difficult to get your partner pregnant.
Boost your omega-3 intake
While the research is still out on supplement sources of omega-3 fatty acids, dietary sources may improve fertility. Salmon, tuna, sardines, and whitefish are a few marine sources; plant sources include flax-seed, chia seeds, plant oils (like canola), and walnuts.
Mind your Fs and Vs
Fruit and vegetables (even a few servings a day) can raise antioxidant and nutrient levels in the blood and sperm by a large amount.
Cool your package
A lower scrotal temperature may be associated with an increase in sperm quantity and quality, so you might want to switch to boxers from briefs, avoid spending too much time in hot tubs or saunas, and keep your laptop on your desk instead of in your lap. I think the impact is minimal, but it may provide a small advantage.
What Else to Know About Men Infertility?
Varicocele is arguably becoming one of the most common and treatable causes of male infertility. An abnormal enlargement of the veins leading away from the testicles, a varicocele is caused by a backward blood-flow (kind of like varicose veins of the testicle). It’s generally harmless, but it can alter the sperm production environment. A specialist can fix a varicocele on an out-patient basis (ask for microsurgical repair if available).