Spermmaxxing: Do Ice, Red Light, and Supplements Really Work?

Ice Baths for the Testicles: Does Cold Help Sperm?

One of the most striking spermmaxxing trends is cooling the testicles. On social media, ice baths and ice packs are among the methods recommended for this purpose. The reasoning sounds plausible at first: the testicles are located outside the body because a lower temperature benefits sperm production. If too much heat is harmful — shouldn't extra cold be especially beneficial?

It's not quite that simple. "The testicles are located outside the body in the scrotum for good reason. Normal spermatogenesis requires a slightly lower temperature than the body's core temperature. Significant or repeated heat exposure can impair spermatogenesis; heat is also one of the known environmental factors that can affect male reproductive function," explains Kaminski.

The key logical error lies in the reverse conclusion. "But that does not mean 'the colder, the better.' There is no convincing evidence that regular ice baths or ice packs improve pregnancy or live birth rates in healthy men."

On the contrary, extreme cold can itself become a problem. "I would therefore not recommend placing ice directly on the scrotum. Extreme cold can damage skin and tissue. It makes more sense to reduce unnecessary prolonged and intense heat exposure — rather than actively cooling the testicles down."

"Testicle Tanning": What Does Sun and Red Light on the Testicles Actually Do?

Even more unusual is another trend that keeps surfacing among male biohackers: so-called "testicle tanning." Sunlight or UV light or red light directed at the testicles is claimed to increase testosterone levels and improve fertility.

For Kaminski, the matter is straightforward: "There is no solid clinical evidence that 'testicle tanning' meaningfully improves testosterone levels, sperm quality, or male fertility."

This trend in particular illustrates a fundamental problem with many supposed biohacks. "This is a good example of how social media claims often work: a biological mechanism or a small experimental observation gets taken and turned into a concrete treatment recommendation for people. That leap is not scientifically justified."

With sunlight, there is an added risk: the sensitive genital skin is exposed to UV radiation. "Sunburn and long-term UV damage don't suddenly become harmless just because the goal is a supposed testosterone boost," says Kaminski.

The urologist sees no viable alternative in red light therapy either. While so-called photobiomodulation is being investigated experimentally, no recommendation can currently be derived from this research to support irradiating the testicles with red light in order to boost testosterone or fertility.

Kaminski's conclusion is correspondingly brief: "The testicles need neither a sunbed nor red light therapy."

Can Zinc, Selenium, and Co. Improve Sperm?

Another major area of spermmaxxing is less spectacular — but a booming business: dietary supplements. Zinc, selenium, coenzyme Q10, carnitine, vitamins, and antioxidants are all marketed to men who want to have children as ways to support sperm quality. Raw garlic even appears in some social media tips on the subject.

The evidence here is actually more nuanced than with ice or testicle tanning. Some studies do show improvements in individual sperm parameters. What matters, however, is whether this also translates into higher chances of pregnancy and live birth.

This is precisely the question that the WHO examined in its guideline on the prevention, diagnosis, and treatment of infertility, published in 2025. Given the uncertain state of the data, the WHO currently issues neither a recommendation for nor against antioxidants for men with infertility and abnormal semen parameters.

This aligns with Kaminski's assessment: "For antioxidants, zinc, selenium, coenzyme Q10, carnitine, and various vitamin supplements, there are numerous studies. Improvements in individual spermiogram parameters are sometimes observed. The problem, however, is the highly heterogeneous study landscape: different patients, different preparations, different dosages, and different endpoints."

He then raises the question that really matters when it comes to having children: "Does the supplement actually lead to more pregnancies and more healthy births? The evidence for that is far less convincing than many advertising claims suggest. One should therefore not automatically assume that an improved lab parameter means improved fertility."

That doesn't mean dietary supplements are fundamentally unnecessary. When a deficiency has been confirmed, targeted supplementation can be medically appropriate, Kaminski emphasizes. That is, however, an entirely different matter from taking several high-dose supplements without a diagnosed deficiency.

He is equally skeptical of more unusual spermmaxxing tips: "For raw garlic, for example, there is no convincing clinical basis for recommending it as a fertility therapy."

His conclusion: "A balanced diet makes sense — but an evidence-based 'sperm booster' in a bottle doesn't currently exist."

What Men Can Actually Do for Their Fertility

So what remains of spermmaxxing once ice, red light, and supposed sperm boosters are removed from the equation? Mostly measures that are considerably less dramatic.

"Here, the unspectacular measures are actually the most important ones," says Kaminski. The WHO also recommends a healthy lifestyle for people who want to have children, including a balanced diet, physical activity, and avoiding tobacco.

One factor deserves particular attention — especially because it initially seems to have nothing to do with the topic: testosterone.

More testosterone would logically seem to mean greater male fertility — or so one might assume. In fact, exactly the opposite can happen.

"From an andrological perspective, there is one point that is sometimes completely overlooked in the fitness and 'biohacking' scene: externally administered testosterone and anabolic steroids can massively suppress spermatogenesis. More testosterone in the blood does not automatically mean greater fertility."

The reason lies in the hormonal regulation of sperm production. "Exogenous testosterone can reduce intratesticular testosterone concentration by suppressing LH and FSH, and in extreme cases can lead to azoospermia," explains Kaminski. In azoospermia, no sperm can be detected in the ejaculate.

The current guideline of the European Association of Urology (EAU) is equally clear on this point: testosterone therapy should not be used to treat male infertility. For infertile men who use anabolic steroids, the guideline recommends discontinuing them first. The EAU also lists overweight, low physical activity, smoking, and high alcohol consumption as factors associated with poorer sperm quality.

Accordingly, the measures Kaminski actually recommends to men who want to have children are unspectacular: "Beyond that, I would focus on maintaining a healthy body weight, regular exercise, moderate alcohol consumption, and avoiding nicotine and drugs, as well as reducing unnecessary intense heat and pollutant exposure. Any medications should also be reviewed when trying to conceive — but never discontinued independently."

Above all, Kaminski warns against relying too long on self-optimization when there is a genuine desire to have children. If a pregnancy fails to occur, seeking medical evaluation is far more sensible than chasing the next hack from social media.

Or, as Kaminski puts it: "Don't 'hack' the testicles with ice, red light, and supplements — instead, reduce avoidable harmful factors and look for a treatable cause if something seems off. That's less spectacular than 'spermmaxxing,' but far better supported by science."