Topical testosterone gels are generally considered the safest form of testosterone replacement therapy for most men. They produce steady, predictable hormone levels that stay within the normal range, cause relatively few side effects, and avoid the risks unique to injections and implants. That said, no single delivery method is universally safest. The best option depends on your lifestyle, your household, and your specific health profile.
Why Gels and Patches Are Considered Safest
The core safety advantage of topical testosterone, whether applied as a gel, solution, or patch, is hormonal stability. Injections create spikes of above-normal testosterone that slowly fall until the next shot, meaning you spend less time in the healthy range. Gels and patches produce smaller, short-term increases over 24 to 48 hours, and daily reapplication keeps levels consistent. That steadiness matters because the peaks and valleys from injections can drive mood swings, irritability, and fluctuations in energy and sex drive.
Among topicals, gels tend to be better tolerated than patches. Transdermal patches cause skin reactions (itching, redness, irritation) in nearly half of users across clinical trials, a remarkably high rate. Gels are gentler: application site reactions occur in roughly 3 to 5% of men using standard formulations, and most reactions are mild. One head-to-head comparison found significantly fewer skin irritation events with gels than with patches.
The main safety concern unique to gels is secondary exposure. Testosterone can transfer from your skin to a partner or child through direct contact. This is a real risk, particularly for women and children, and the FDA requires a warning about it on gel products. You can minimize it by covering the application area with clothing after the gel dries and washing your hands thoroughly.
How Injections Compare
Injectable testosterone is the oldest and most widely used form of therapy. The two standard options, testosterone cypionate and testosterone enanthate, are given as intramuscular shots every one to two weeks. They’re effective and inexpensive, but they come with trade-offs.
Pain and inflammation at the injection site are common. More importantly, the hormonal roller coaster between injections can affect mood and libido in ways that topical methods avoid. Some men tolerate this well; others find it disruptive.
A longer-acting injectable form, testosterone undecanoate, requires fewer injections (roughly every 10 weeks) but carries a unique risk: a small chance of a serious reaction called pulmonary oil microembolism, where tiny oil droplets enter the bloodstream and reach the lungs. Because of this, every injection must be given in a medical office, and you’re required to wait 30 minutes afterward for observation.
Newer Oral Options
Oral testosterone had a bad reputation for decades because the original formulation, methyltestosterone, was toxic to the liver. Newer oral testosterone undecanoate capsules work differently. They’re absorbed through the lymphatic system rather than passing directly through the liver, and two-year safety data show no clinically significant changes in liver function and no evidence of liver toxicity. This makes modern oral testosterone a reasonable option for men who want to avoid needles and skin application, though it requires taking capsules with food twice daily.
Less Common Delivery Methods
Implantable pellets are inserted under the skin every three to six months. They provide consistent levels without daily effort, but the most common complication, pellet extrusion (the pellet working its way back out), happens in about 10% of cases. Infections, bleeding, and scarring at the insertion site are also possible.
Nasal testosterone gel is applied inside the nose two to three times daily. Side effects include nasal discomfort, nosebleeds, and runny nose in more than 3% of users. It avoids skin transfer risk entirely, which can make it a good fit for men with young children or partners who are pregnant or could become pregnant. Buccal tablets, placed against the gum, cause mouth irritation or gum inflammation in about 18% of users, which limits their appeal.
Cardiovascular Safety Across All Forms
For years, the biggest concern about any testosterone therapy was heart risk. The TRAVERSE trial, published in the New England Journal of Medicine, was designed specifically to answer this question. It followed over 5,000 men with low testosterone who either had existing cardiovascular disease or multiple risk factors for it. After an average of 22 months, major cardiac events (heart attack, stroke, or cardiovascular death) occurred in 7.0% of men on testosterone and 7.3% on placebo. The difference was not significant, and the FDA responded by removing the cardiovascular warning from testosterone product labels.
One finding that did hold up: testosterone therapy can raise blood pressure modestly. The FDA now requires blood pressure warnings on all testosterone products. This is worth monitoring but is manageable for most men.
Prostate Cancer Risk
Testosterone therapy does not appear to increase prostate cancer risk in the general population. The TRAVERSE trial found similar cancer rates in both the testosterone and placebo groups over 33 months. Even among men with a family history of prostate cancer, a matched study of over 1,200 patients found no significant difference in cancer diagnoses or active treatment over 10 years.
There is a nuance worth noting. In that family-history study, the testosterone group actually had a lower risk in the first year (0.2% vs. 2.3%), but by year 10, their cumulative incidence was higher (21.7% vs. 12.4%). This time-dependent pattern suggests that men on long-term therapy, especially those with family risk factors, benefit from more frequent PSA testing as the years go on.
The Risk That Applies to Every Method
Regardless of how testosterone enters your body, it increases red blood cell production. This is the most common systemic side effect of any form of testosterone therapy. When red blood cell concentration gets too high, a condition called erythrocytosis, blood becomes thicker and the risk of clots rises. American guidelines recommend against starting testosterone if your hematocrit (the percentage of blood volume occupied by red cells) is already above 50%. If it climbs above 54% during treatment, therapy should be stopped and blood donation or phlebotomy may be needed to bring levels down. Once hematocrit drops below 50% again and no other cause is found, treatment can typically restart at a lower dose.
This is why blood monitoring is non-negotiable on any testosterone regimen. The Endocrine Society recommends checking hematocrit at baseline, again at 3 to 6 months, and then annually. PSA levels should be checked before starting therapy and again at 3 to 12 months for men over 40 with elevated prostate cancer risk, or men 55 to 69 regardless of risk factors.
Fertility Is a Separate Safety Concern
Testosterone therapy suppresses sperm production. When you add testosterone from outside the body, your brain reduces its signals to the testes, and sperm output can drop to zero. The Endocrine Society recommends against testosterone therapy for men planning to have children in the near term. If you need treatment for low testosterone but want to preserve fertility, alternatives like clomiphene citrate or HCG can raise testosterone levels without shutting down sperm production. HCG in particular has been used alongside testosterone in some cases, with studies showing it can maintain a degree of testicular function, though this approach has limitations and isn’t yet standard practice.
Choosing the Safest Option for You
For most men, a testosterone gel offers the best balance of safety, effectiveness, and tolerability. It keeps hormone levels stable, has a low rate of side effects, and avoids the procedural risks of injections and pellets. If you live with children or a partner who could be harmed by skin transfer, nasal testosterone or the newer oral capsules eliminate that concern. Injections remain a reasonable choice for men who prefer less frequent dosing and don’t mind the hormonal fluctuation, though they’re harder to fine-tune.
What matters more than the delivery method is consistent monitoring. Every form of testosterone therapy carries the same core risks: thickening blood, modest blood pressure increases, and the need for ongoing prostate screening. The safest testosterone treatment is ultimately the one paired with regular blood work and a provider who adjusts the dose based on what the numbers show.