Understanding Oral Testosterone: Benefits, Risks, and Options for Men

For many men, low testosterone has a slow onset: less energy, a drop in sex drive, trouble focusing, or a general sense that something doesn't feel right. These common signs of hypogonadism are caused by low serum testosterone levels. Low testosterone (low T) is estimated to affect between 10 and 40% of men globally, but the condition often goes undiagnosed (Corona et al., 2010).

Testosterone replacement therapy (TRT) has been used since the 1940s to treat low testosterone levels, but self-administered injections or creams don't suit everyone. That’s why oral testosterone has made treatment more accessible and convenient. Since the FDA approved testosterone undecanoate capsules in 2019, oral testosterone has grown in popularity.

The way they work sets these newer oral formulations apart from their older counterparts. Older pills were once broken down by the liver, which reduced their effectiveness and raised concerns about liver toxicity, a serious risk that can lead to liver stress or damage over time. Today’s oral testosterone is absorbed through the lymphatic system instead. This bypasses the liver entirely, making the treatment both safer and more convenient for long-term use.

Key Takeaways

• Male hypogonadism affects millions of men and is frequently underdiagnosed and undertreated.
• Testosterone replacement therapy (TRT) options include gels, patches, injectables, and new oral testosterone undecanoate formulations.
• Oral testosterone replacement therapy (oral TRT) is a convenient method of testosterone administration.
• Oral testosterone undecanoate does not pass through the liver to be metabolized, making it a safer treatment option.

The Role of Testosterone in the Body

Testosterone helps regulate processes in the body: sexual function, mood, and energy levels. It also influences bone density and the production of red blood cells. When testosterone levels fall, it can cause a slow but noticeable change in how a man feels and functions.

Testosterone levels decrease naturally with age but can drop more noticeably in some men, resulting in a testosterone deficiency. Low testosterone levels can also be caused by injury, illness, cancer treatment, or conditions that affect the pituitary gland.

What Makes New Oral Testosterone Formulations Different?

Older formulations of oral testosterone options weren’t ideal. They passed through the liver, posing risks like liver toxicity. This process is called first-pass metabolism. Over time, this could lead to elevated liver enzymes, liver cell damage, reduced bile flow (cholestasis), and in rare cases, liver tumors. Because of these risks, such formulations are rarely used in modern clinical practice.

Modern formulations avoid that problem by using the lymphatic system for absorption. The testosterone gets into the bloodstream through the gut’s lymphatic vessels instead of being processed in the liver. That makes it a safer route for long-term use.

Furthermore, newer testosterone pills don’t require a high-fat meal to work properly, and they come in fixed doses, which simplifies the routine for patients. However, health professionals recommend that you take oral testosterone with food, as this can assist with absorption.

How Oral Testosterone Works in the Body

Testosterone undecanoate can enter the systemic circulation thanks to the intestinal lymphatic absorption mechanism. As a result, testosterone levels may stay more constant throughout the day. This stability helps support better mood regulation, improved energy levels, and more consistent libido, without the highs and lows often associated with fluctuating hormone levels.

Benefits of Oral Testosterone Undecanoate for Low T

One of the most appealing benefits of oral testosterone is its convenience. You take it at the same time each day (usually morning and evening), and it maintains a steady level of testosterone in your blood.

Clinical data show these oral formulations raise testosterone levels into the normal range for most users. Symptoms like low libido and fatigue often improve once testosterone levels are stable and within the normal range. And because you’re not dealing with injections or creams, compliance tends to be higher.

Patient Types Suited for Oral TRT

Oral testosterone may be useful for:

• Men with secondary hypogonadism
• Those unable or unwilling to use injections or gels
• Patients with busy or unpredictable schedules
• Men who are concerned about transferring topical gels to partners or children

Patients should undergo regular follow-ups to monitor blood pressure, hematocrit, and lipids. Monitoring is typically done with a blood test a few hours after you take your morning dose of testosterone. Your healthcare provider will adjust your treatment plan based on these test results.

Side Effects of Oral Testosterone Replacement Therapy

Ask about the risks associated with testosterone replacement therapy, regardless of the administration method you choose. All forms of testosterone treatment may cause mood changes, oily skin, and higher red blood cell counts.

If you are taking oral testosterone replacement therapy, familiarize yourself with the risks associated with capsules. One of the more important side effects is its potential impact on blood pressure. The FDA has highlighted this in product labeling, especially for patients with a history of heart problems or stroke.

Other concerns include elevated red blood cell counts, changes in cholesterol levels (especially LDL cholesterol), and, in rare cases, blood clots. However, recent meta-analyses have shown no clinically significant increase in the risk of venous thromboembolism (VTE) with testosterone therapy. Despite this reassuring data, it's still essential to monitor for signs of VTE during treatment, particularly in patients with other risk factors.

These risks show why medical supervision and monitoring of ambulatory blood pressure during regular follow-up appointments are important. Risks can be managed, but only if they’re tracked by a medical professional.

Picking the Right Form of Testosterone Replacement Therapy

Testosterone replacement therapy (TRT) should be customized and built around your preferences and health needs. Some men can stabilize their testosterone levels with injectable and topical forms, while others prefer the convenience of oral therapy.

Each form has a set of pros and cons. Topical gels, for example, can transfer to other people if you’re not careful. Injections tend to cause peaks and dips in hormone levels, which some men find disruptive. Patches can cause skin irritation.

Clinical Research and Monitoring

Testosterone therapy is easy to monitor. If you are on a fixed dose, your healthcare provider can assess testosterone levels with a single blood sample. The sample is usually taken a few hours after the morning dose of testosterone.

Clinical trials on oral testosterone products have shown consistent absorption and hormone stability (Goldstein et al., 2025). This is relevant because free testosterone and total testosterone levels need to remain within the normal range to avoid symptoms.

References

Bhasin, S., et al. (2018). "Testosterone Therapy in Men with Hypogonadism: An Endocrine Society Clinical Practice Guideline." The Journal of Clinical Endocrinology & Metabolism, 103(5), 1715–1744.

U.S. Food & Drug Administration. (2019). “FDA Approves New Oral Testosterone Undecanoate Capsule for Treatment of Men with Certain Forms of Hypogonadism.”

Lipshultz, L. I., et al. (2020). “A New Oral Testosterone Undecanoate Therapy (JATENZO®) for Hypogonadal Men: Efficacy and Safety Results from Phase 3 Clinical Trials.” The Journal of Urology, 204(4), 747–755.

Morgentaler, A., et al. (2020). “Testosterone Therapy in Men with Hypogonadism: An Update.” Nature Reviews Urology, 17(3), 190–202.

Kaminetsky, J., et al. (2019). “Oral Testosterone Undecanoate Therapy Results in Physiologic Testosterone Levels and Is Well Tolerated.” Andrology, 7(6), 867–877.

American Urological Association. (2018). “Evaluation and Management of Testosterone Deficiency: AUA Guideline.”

Corona, G., Maseroli, E., & Maggi, M. (2014). Hypogonadism and sexual dysfunction in elderly men: Results from the European Male Aging Study. Clinical Endocrinology, 81(5), 748–757.

Ayele HT, Brunetti VC, Renoux C, Tagalakis V, Filion KB. Testosterone replacement therapy and the risk of venous thromboembolism: A systematic review and meta-analysis of randomized controlled trials. Thromb Res. 2021 Mar;199:123-131.