When you start testosterone therapy, testosterone itself is only one piece of the picture. Most men on TRT benefit from at least one or two additional medications or supplements to manage side effects, protect fertility, and keep blood markers in a healthy range. What you need depends on your goals, your lab work, and whether you plan to have children, but a few categories come up consistently.
HCG for Fertility and Testicular Function
Exogenous testosterone signals your brain to stop producing its own, which means your testes gradually shrink and sperm production drops, sometimes to zero. If you want to preserve fertility or simply avoid testicular atrophy, human chorionic gonadotropin (HCG) is the most common addition to a TRT protocol. HCG mimics the hormone that normally tells your testes to produce testosterone and sperm, keeping them active even while you’re getting testosterone from an outside source.
For men who’ve already experienced low sperm counts on TRT, research published in Fertility and Sterility has explored using HCG alongside follicle-stimulating hormone (FSH) to restore spermatogenesis more effectively than older approaches like clomiphene alone. In practice, many prescribing clinicians add HCG from the start of therapy rather than waiting for problems to develop. Typical protocols involve small injections two to three times per week.
Estrogen Management
Your body converts a portion of testosterone into estrogen through a process called aromatization. At normal levels, estrogen is important for bone health, brain function, and cardiovascular protection. But when testosterone doses push estrogen too high, you can experience water retention, breast tissue growth (gynecomastia), reduced sex drive, difficulty focusing, and erectile dysfunction.
Aromatase inhibitors like anastrozole block that conversion. A common starting dose is 0.5 mg twice per week, though many clinicians now take a more conservative approach: they wait for bloodwork to confirm elevated estradiol before prescribing one rather than adding it automatically. The target range most practitioners aim for is an estradiol level between 20 and 30 pg/mL, though individual tolerance varies. Some men feel fine at levels above that range, while others notice symptoms earlier. Regular blood tests are the only reliable way to know whether you need estrogen control.
Enclomiphene as an Alternative or Add-On
Some men use selective estrogen receptor modulators (SERMs) either alongside testosterone or as a standalone alternative. Enclomiphene, a newer option, has shown advantages over traditional clomiphene (Clomid). In a study of 66 patients published in the Journal of Urology, enclomiphene raised testosterone by a median of 166 ng/dL while actually lowering estradiol by about 6 pg/mL. Clomiphene, by contrast, increased estradiol by 17.5 pg/mL.
Side effects were also significantly lower with enclomiphene. Patients reported less decreased libido, fewer mood changes, and better energy levels compared to clomiphene. For men who want to raise testosterone without injections, or who need to maintain fertility that standard TRT would compromise, enclomiphene is increasingly prescribed as a first-line option.
Key Supplements: Zinc, Magnesium, and Vitamin D
Micronutrient deficiencies can quietly undermine your hormonal health. Three nutrients come up repeatedly in the testosterone conversation.
Zinc is directly involved in testosterone production. Deficiency is surprisingly common, especially in men who sweat heavily through exercise. Supplemental doses of around 30 mg per day (about 270% of the daily value) are typical in formulations designed for hormonal support.
Magnesium plays a role in over 300 enzymatic processes, including those related to sleep quality and muscle recovery, both of which influence hormonal output. Supplemental doses of around 450 mg per day are standard. Many men on TRT find that magnesium also helps with the muscle cramps and sleep disruptions that can accompany hormonal fluctuations.
Vitamin D functions more like a hormone than a vitamin, and low levels are strongly associated with low testosterone. If your bloodwork shows you’re below the optimal range (generally 40 to 60 ng/mL), supplementing with 2,000 to 5,000 IU daily is a reasonable starting point. These three nutrients won’t replace medical therapy, but correcting deficiencies removes a drag on your system that no prescription can fix.
Boron for Free Testosterone
Most of your testosterone is bound to a protein called sex hormone-binding globulin (SHBG), which makes it unavailable for your body to use. Boron, a trace mineral, has shown a meaningful ability to lower SHBG and increase the free testosterone that actually reaches your tissues. In a study published in the Journal of Trace Elements in Medicine and Biology, men taking 10 mg of boron daily saw a significant increase in free testosterone and a decrease in estradiol after just one week. Inflammatory markers also dropped. Boron is inexpensive, widely available, and one of the few supplements with direct evidence for shifting the free-to-bound testosterone ratio.
Blood Work You Need to Monitor
Taking testosterone without monitoring your blood is like driving without a dashboard. Two markers deserve particular attention.
Hematocrit measures how much of your blood volume is made up of red blood cells. Testosterone stimulates red blood cell production, which is beneficial up to a point but dangerous beyond it. Thick blood increases your risk of clots, stroke, and heart attack. The American Urological Association recommends a baseline measurement before starting therapy and repeat testing every 6 to 12 months. If your hematocrit exceeds 50% before starting, your clinician should investigate why before prescribing. Once on therapy, a reading at or above 54% requires intervention, which could mean dose reduction, therapeutic blood donation, or temporarily stopping treatment.
PSA (prostate-specific antigen) should be measured in men over 40 before starting testosterone. While testosterone therapy does not cause prostate cancer, it can accelerate the growth of an existing undetected cancer. The AUA recommends ongoing PSA testing using a shared decision-making approach, meaning you and your doctor decide on frequency based on your individual risk factors.
Resistance Training as a Force Multiplier
What you do in the gym matters as much as what you take from a bottle. Heavy compound movements like squats, deadlifts, and bench presses produce acute spikes in circulating hormones that complement TRT. Research in the Journal of Applied Physiology has shown that these hormonal responses depend on specific training variables: higher intensity, larger muscle groups, and shorter rest periods between sets all amplify the effect. Protocols using lighter weights, isolation exercises, or long rest intervals produce a much weaker hormonal response.
For men on TRT, resistance training also improves insulin sensitivity, body composition, and sleep quality, all of which feed back into how effectively your body uses the testosterone you’re providing it. Three to four sessions per week built around multi-joint lifts with 60 to 90 seconds of rest between sets is a solid framework.
Putting It All Together
Not every man on testosterone needs every item on this list. A reasonable starting framework looks like this:
- HCG: Add from the start if fertility matters to you, or if you want to prevent testicular atrophy.
- Aromatase inhibitor: Only if bloodwork confirms elevated estradiol or you develop symptoms of high estrogen.
- Zinc, magnesium, vitamin D: Correct any deficiencies. Test levels first if possible.
- Boron: 10 mg daily to support free testosterone and lower SHBG.
- Regular bloodwork: Hematocrit and estradiol every 6 to 12 months at minimum. PSA if you’re over 40.
- Resistance training: Heavy compound lifts, three to four times per week.
Your specific protocol should be guided by lab results, not guesswork. The difference between men who thrive on TRT and those who struggle with side effects almost always comes down to whether ancillary support and monitoring are part of the plan.