Do testosterone boosters work? What the research shows

Do testosterone boosters work? For most men, the evidence says not much. "Testosterone booster" is a marketing category, not a medical one. The bottles promise more energy, muscle, drive and confidence, and they sell to men who feel tired and flat and have read that their testosterone is to blame. Sometimes it is. Usually something else is, and a supplement won't tell you which.

This guide covers what low testosterone means to a doctor, what researchers found when they checked T-booster claims against the literature, the evidence for the common ingredients, the risks (including products spiked with real hormones), how prescription testosterone differs, and the unglamorous things that do raise testosterone in many men. If your main problem is erections rather than energy or desire, read our guide to ED treatments that work first: low testosterone is a less common cause of ED than most men assume.

What "low T" actually means

The American Urological Association's guideline on evaluation and management of testosterone deficiency (published 2018, reviewed and confirmed valid in 2024) is the standard US reference. Its core rule is that a man counts as testosterone deficient, and a candidate for treatment, only when he has both low testosterone levels and symptoms or signs that go with them.

• The number. The AUA uses a total testosterone below 300 ng/dL as a reasonable cutoff. The large TRAVERSE trial, for example, enrolled men with two readings below 300 ng/dL plus symptoms.
• Two morning tests. Testosterone is highest in the morning and varies day to day, so one low reading isn't a diagnosis. The guideline calls for two early-morning measurements on different days.
• The symptoms. Low sex drive, fewer morning erections, erectile problems, fatigue, low mood, loss of muscle and increased body fat. All of these have many other causes, which is exactly why the blood test matters.

True deficiency is less common than the advertising implies. In the European Male Ageing Study of men aged 40 to 79, only about 2% met strict criteria for late-onset hypogonadism (low testosterone together with three sexual symptoms), though low readings were more common in older and heavier men. Many more men have a borderline number and vague symptoms, and for them the cause is often weight, sleep, alcohol, medicines or another illness.

What researchers found when they checked the bottles

The most useful study for a shopper is a 2020 analysis from the University of Southern California, published in the World Journal of Men's Health. The researchers took 50 "T booster" supplements found through Google, listed their ingredients (109 different ones, a mean of 8.3 per product) and searched the medical literature for evidence behind each.

• 90% of the products claimed to boost testosterone.
• Only 24.8% had published data showing their ingredients increase testosterone. 18.3% had data showing no change, and 10.1% contained ingredients with data suggesting they lower testosterone.
• No data at all existed for 61.5%.
• Many contained huge doses of vitamins (a median of 1,291% of the daily requirement for B12), and 13 products exceeded the FDA's upper limits for zinc, niacin or magnesium.

The authors' conclusion was blunt: men should be told these supplements may not contain ingredients that support their claims. Note what this study tested: whether the ingredients have evidence, not whether the products themselves work. Hardly any T-booster product has been tested as a finished product in a published placebo-controlled trial.

Which testosterone booster ingredients work?

Ashwagandha

An Ayurvedic herb that appears in most modern formulas. The NIH Office of Dietary Supplements' ashwagandha fact sheet reviews small trials suggesting it might modestly raise testosterone in some men, and also notes rare reports of liver injury and possible effects on thyroid hormones. Several of the positive trials were funded by makers of branded extracts.

Tongkat ali (Eurycoma longifolia)

A Southeast Asian root with one of the more encouraging evidence bases here. A 2022 meta-analysis pooled five randomized trials and found tongkat ali raised total testosterone, particularly in men who were hypogonadal to begin with. The authors still said more research is needed before clinical use. The trials were small, and most tested specific standardized extracts that may not match what is in a given bottle.

D-aspartic acid

An amino acid that was popular after early studies in untrained men. In a 12-week randomized trial in resistance-trained men, 6 grams a day did not change testosterone, and the authors note an earlier study in trained men that found a drop. It is a good example of an ingredient whose headline claim did not survive better trials.

Tribulus terrestris

Sold for decades as a testosterone herb. In a Brazilian placebo- controlled trial in men with erection problems, tribulus did not raise testosterone or improve erections more than placebo. Our ingredients guide covers the mixed results in more detail.

Fenugreek, maca and boron

Fenugreek is supported mainly by small industry-funded trials of branded extracts, with libido more often reported than large testosterone changes. Maca is sold for libido rather than hormones, and a systematic review found only limited evidence for any sexual benefit. Boron has a few tiny short-term studies. None of the three is a reason to buy a product.

Zinc and vitamin D

Real deficiency of either can lower testosterone, and correcting a deficiency is worthwhile. Topping up normal levels is different. In a randomized trial of 100 healthy Austrian men with low testosterone and low-to-normal vitamin D, high-dose vitamin D for 12 weeks had no effect on testosterone. For zinc, the NIH sets an upper limit of 40 mg a day for adults, and the USC study found T-boosters that exceeded it; long-term excess zinc can cause copper deficiency.

Are testosterone boosters safe?

Products that contain real hormones

The bigger danger is not a herb that does nothing. It is a "natural" product that works because it contains something that isn't on the label. The FDA warns that some bodybuilding products may illegally contain steroids or steroid-like substances, and that it has adverse event reports showing serious liver injury. Hidden anabolic steroids can shut down your own testosterone production, damage the liver and affect fertility. Products marketed with words like "anabolic", "pro-hormone" or "SARM", or promising dramatic muscle gains in weeks, are in this territory. Our guide to tainted sexual-enhancement products explains how to check the FDA's lists.

Interactions and side effects

• Ashwagandha: rare liver injury; may affect thyroid tests and interact with sedatives, thyroid and immune-suppressing drugs, per the ODS fact sheet.
• Fenugreek: can lower blood sugar, relevant if you take diabetes medicine.
• Megadose vitamins and minerals: the USC analysis found products over the FDA upper limits.
• Masking a real problem: fatigue, low mood and low libido can come from depression, sleep apnea, thyroid disease, diabetes or medicines. A bottle delays finding out.

Prescription testosterone is a different thing

If blood tests confirm deficiency, prescription testosterone (gels, injections, patches, pellets and an oral form) reliably raises levels; that is what it is approved for. It is not a lifestyle drug, and the FDA says testosterone is approved only for men with low or absent testosterone together with an associated medical condition, keeping a limitation of use for age-related low testosterone alone.

The heart question

For years the labels carried a boxed warning about possible cardiovascular risk. The TRAVERSE trial tested that directly in 5,246 men aged 45 to 80 with low testosterone and either heart disease or high cardiovascular risk, and found testosterone gel was not worse than placebo for major heart events. It did see more atrial fibrillation, acute kidney injury and pulmonary embolism in the testosterone group. In February 2025 the FDA ordered class-wide label changes: TRAVERSE results added, the cardiovascular language removed from the boxed warning, and blood-pressure warnings kept and expanded.

Fertility

This surprises a lot of men: prescription testosterone lowers sperm production, because the body reads the outside hormone as a signal to stop making its own and switches off the testicles' sperm factory. The AUA guideline addresses men who want to preserve fertility separately, and men trying to have children should not start testosterone without discussing alternatives with a urologist. The MedlinePlus testosterone page lists the other side effects and monitoring (blood counts, PSA, blood pressure).

How to get tested properly

A blood test is cheap compared with months of supplements, and it is the only way to know whether testosterone is your problem at all.

• Ask for a morning total testosterone test, drawn early (the AUA guideline's approach), and repeat it on another morning if the first is low. A single afternoon test after a bad night's sleep can mislead you.
• Expect follow-up tests if it is low. Doctors typically check the pituitary hormones that drive testosterone production (LH and FSH), and sometimes prolactin, iron and other markers, to find out why it is low. The cause changes the treatment.
• Mention your symptoms and medicines, including any supplements. Some contain ingredients that can distort results, and biotin in high doses is known to interfere with some lab tests.
• Be wary of clinics that sell the cure with the test. A "low T clinic" that diagnoses almost everyone and prescribes on the first visit is not following the two-test, symptoms-plus-numbers rule.

If your levels are normal, that is useful news: it points you toward the real cause of the fatigue or low drive, and it saves you money on boosters.

How to raise testosterone naturally

For men whose low readings are driven by lifestyle rather than disease of the testicles or pituitary, the most reliable interventions are not sold in bottles.

• Losing weight. A 2013 meta-analysis of 24 studies found weight loss raised testosterone, and the more weight lost, the bigger the rise; low-calorie diets helped and bariatric surgery more so. Fat tissue converts testosterone to estrogen, so this is not a coincidence.
• Sleeping enough. In a small University of Chicago study, healthy young men limited to five hours a night for one week had daytime testosterone 10% to 15% lower than after a week of full nights. Untreated sleep apnea is also linked with low testosterone and is worth asking about if you snore and wake up tired.
• Exercise, including resistance training, which also helps with the weight, the mood and the erections.
• Less alcohol and no opioids where you can avoid them; opioid painkillers are a well-known cause of low testosterone.
• Reviewing medicines and illnesses with a doctor, including diabetes, which is strongly associated with low testosterone.

What is a normal testosterone level for a man?

The AUA guideline uses a total testosterone below 300 ng/dL, on two separate early-morning blood tests and together with symptoms, as the threshold for deficiency. A single low reading, or a low number without symptoms, is not enough for a diagnosis.

Does tongkat ali raise testosterone?

There is some evidence: a 2022 meta-analysis of five small randomized trials found it raised total testosterone, especially in men who were low to begin with. The authors said more research is needed, and the extract in a given bottle may not match the ones tested.

Do testosterone boosters help with erections?

Rarely. Low testosterone mainly lowers desire, and testosterone therapy on its own often does not fix erectile dysfunction even in men who are truly deficient. Erection problems usually have other causes that a doctor can treat.

Our Innerbody testosterone review and the full supplement comparison apply this evidence to specific products.

If you still want to try a supplement

Choose one that lists every ingredient's dose (no proprietary blend), avoids megadoses above the NIH upper limits, makes no steroid-like promises, and offers a real refund on opened bottles. Get a morning testosterone test before you start, so you have something to compare against, and tell your doctor what you're taking. Our review of Innerbody Labs Testosterone Support covers one product that meets the disclosure part of that list, along with the conflict of interest in how it is reviewed elsewhere and the fact that it has no trial of its own.

And if what you actually want is better erections, testosterone is rarely the shortest path. Read what works for ED, and if size is the worry, our look at enlargement claims.