10 Testosterone Myths Debunked: What Science Actually Says

The internet is full of testosterone advice, and a significant portion of it is wrong. Some myths are harmless. Others cause men to waste money on supplements, avoid perfectly healthy foods, or ignore the habits that matter. Below, we check 10 persistent testosterone myths against published research and rate each one: TRUE, PARTIAL (contains a kernel of truth but is misleading), FALSE (contradicted by the evidence), or UNPROVEN (popular, but we found no solid human evidence).

Myth 1: Soy Lowers Testosterone: FALSE

A 2021 meta-analysis in Reproductive Toxicology pooled 41 clinical studies (total testosterone was measured in 1,753 men) and found no significant effects of soy protein or isoflavone intake on total testosterone, free testosterone, estradiol or estrone. Sub-analyses by isoflavone dose and study duration also showed no effect.^[1] The myth persists because soy contains phytoestrogens, which sounds alarming. For a deep dive, read our full analysis of soy and testosterone.

Myth 2: Cold Showers Significantly Boost Testosterone: UNPROVEN

This is one of the most popular claims in the biohacking space. While cold exposure may help some people feel more alert, we did not find well-designed human trials showing that cold showers meaningfully raise testosterone, so the claim is unproven. Cold showers may be worth trying for how they feel, but they should not be treated as a testosterone intervention. The same caution applies to red light therapy.

Myth 3: Abstaining from Ejaculation Raises Testosterone: FALSE

The most cited evidence for this claim is a 2003 paper reporting a large testosterone spike after seven days of abstinence. That paper was retracted in December 2021, so it should not be used as evidence.^[2] We are not aware of reliable trial evidence that abstinence raises testosterone over the long term. Some men report psychological benefits from NoFap practices, but those are separate from testosterone. The broader question of whether sex increases testosterone is more nuanced than the abstinence debate suggests.

Myth 4: Bald Men Have Higher Testosterone: FALSE

Male pattern hair loss is driven by the progressive miniaturization of scalp hair, and research points to dihydrotestosterone (DHT) acting in the scalp as a key factor. The case rests on observations in men with genetic 5-alpha-reductase deficiency, who have low DHT, and on controlled trials in which finasteride, which lowers scalp DHT, improved scalp hair growth.^[5] The focus is on how DHT acts on follicles, not on how much testosterone circulates in the blood, so hair loss is not a reliable sign of high testosterone. For more, see our article on testosterone and hair loss. If hair loss concerns you, a dermatologist or doctor can discuss options.

Myth 5: Eating Eggs Significantly Boosts Testosterone: PARTIAL

Eggs provide cholesterol (the starting material the body uses to make steroid hormones, including testosterone), protein and other nutrients. But your body also makes its own cholesterol, and we are not aware of trials showing that eating eggs raises testosterone in men who already eat adequate protein and fat. Eggs fit into a testosterone-supportive diet, but they are not a hormonal intervention on their own.

Myth 6: Testosterone Booster Supplements Work: PARTIAL

A review of 50 popular "T booster" supplements found 109 unique ingredients, with an average of 8.3 per product. Ninety percent of the products claimed to boost testosterone, but only 24.8 percent had published data showing an increase in testosterone, 10.1 percent had data showing a decrease, 18.3 percent showed no change, and no data were found for 61.5 percent. Some products also contained several times the recommended daily allowance of certain vitamins and minerals, and thirteen exceeded the US upper tolerable intake level for zinc, niacin or magnesium.^[3]

There is a kernel of truth: correcting a true nutrient deficiency can matter. In one small study, zinc restriction in healthy young men was followed by lower testosterone, and zinc supplementation in marginally zinc-deficient older men was followed by higher testosterone.^[6] That does not mean extra zinc helps men who are not deficient, and high doses carry their own risks. If you are considering supplements, see our guide to testosterone supplements and speak to a doctor or pharmacist first, especially if you take medication. Our article on creatine and testosterone covers a common example.

Myth 7: Sugar Lowers Testosterone: TRUE (Short Term)

There is evidence for an acute effect. In a study published in Clinical Endocrinology, 74 men aged 19 to 74 underwent a standard 75 g oral glucose tolerance test. Glucose ingestion was associated with a 25 percent decrease in mean testosterone levels, and the decrease was similar across normal, impaired and diabetic glucose tolerance. The authors concluded that men with low non-fasting testosterone should be re-evaluated in the fasting state.^[4] A 75 g glucose drink is not a typical meal, and the study did not show long-term effects. For more detail, read our article on sugar and testosterone.

Myth 8: Testosterone Inevitably Crashes After 30: PARTIAL

Testosterone does decline with age, but gradually. In the Massachusetts Male Aging Study, which followed 1,156 men aged 40 to 70 at baseline, total testosterone declined about 0.8 percent per year in cross-sectional comparisons and 1.6 percent per year within the same men over 7 to 10 years. The authors also reported that apparent good health (no chronic illness, prescription medication, obesity or excessive drinking) added 10 to 15 percent to several androgen levels, and suggested that incident poor health may accelerate the decline.^[7] Age is a factor, and so are modifiable health conditions. Learn more in our guide to testosterone after 40.

Myth 9: TRT Is the Same as Anabolic Steroids: FALSE

Testosterone replacement therapy (TRT) is a prescription treatment for diagnosed hypogonadism. The Endocrine Society guideline recommends diagnosing hypogonadism only in men with symptoms and signs consistent with testosterone deficiency and unequivocally and consistently low serum testosterone, confirmed by repeat morning fasting tests, and recommends treatment only after discussing benefits, risks and monitoring. It also recommends against starting therapy in men planning fertility in the near term or with conditions such as breast or prostate cancer.^[8] Anabolic steroid abuse is a different situation: unsupervised, non-medical use of drugs for performance or appearance. Never start testosterone or any anabolic drug without a doctor. For a nuanced comparison, see our TRT vs. natural optimization guide.

Myth 10: High Testosterone Makes You Aggressive: PARTIAL

The truth sits in between. A widely cited review concluded that in men, high endogenous testosterone seems to encourage behavior intended to dominate or raise status over other people, that dominant behavior is sometimes aggressive but often expressed non-aggressively, and that testosterone and dominance affect each other in both directions.^[9] Another review reports higher testosterone in some groups with aggressive behavior, and rising testosterone in winners of competitions, while stressing the roles of brain circuits, cortisol and serotonin.^[10]So the statement "high T makes you aggressive" oversimplifies a complex, two-way relationship.

A related myth is that testosterone therapy causes prostate cancer. In the TRAVERSE randomized trial of 5,204 men with hypogonadism who had or were at risk of cardiovascular disease, high-grade prostate cancer occurred in 5 of 2,596 men on testosterone gel (0.19 percent) and 3 of 2,602 on placebo (0.12 percent), a difference that was not statistically significant over an average of about 22 months.^[11] That does not mean TRT is suitable for everyone, and it does not cover longer follow-up, so prostate monitoring remains a conversation for you and your doctor. See testosterone and prostate health.

Myth Scorecard

What Is Better Supported

Rather than chasing myths, focus on habits with a stronger evidence base for overall and hormonal health. None of these is a guaranteed fix, and persistent symptoms are a reason to see a doctor.

The weight-loss finding comes from a systematic review of men with obesity, so it applies most to men who are carrying excess weight.^[12]

The Bottom Line

Most testosterone myths take a tiny grain of truth (or none) and inflate it into a dramatic claim that spreads easily on social media. Healthy habits like sleep, training, body composition, stress management and nutrition quality are a sensible place to put your effort. If you have symptoms such as persistent fatigue, low sex drive or low mood, talk to a doctor about testing rather than relying on internet advice. This article is educational and not medical advice.

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