How Long Does Testosterone Replacement Therapy Typically Last?

Written by Leann Poston, M.D.

Testosterone therapy can relieve many of the side effects of age-associated low testosterone levels. Before starting treatment, most men want to know how long it will take to restore their vigor and how long testosterone therapy lasts. 

Hypogonadism, or low testosterone levels, affects approximately 4-5 million men in the United States (Seftel, 2006). Testosterone levels are at their highest during adolescence and early adulthood. After the age of 30 to 40, testosterone production begins to decline at a rate of about 1% per year. According to the Baltimore Longitudinal Study on Aging, 20% of men in their 60s, 30% of men in their 70s, and 50% of men over the age of 80 have symptoms related to low testosterone levels (Harman, 2001). Low testosterone levels affect up to 4 million American men, yet only about 5% of men with documented low testosterone levels receive treatment (Seftel, 2005).

Knowing these facts may reassure you that you are not alone, but they do not address the issue. It seems simple enough, if you are low on testosterone, whether due to aging or a medical condition, testosterone replacement should alleviate and potentially even reverse your symptoms. Let’s take a look at what symptoms you can expect testosterone therapy to help with and how long most men typically stay on testosterone therapy. 

Learn More: What Is Testosterone Replacement Therapy?

Normal Testosterone Levels

Doctors diagnose age-related hypogonadism based on two factors: low testosterone levels and symptoms of low testosterone. Before we get into how long testosterone therapy lasts, let’s look at the recommended lab tests and the symptoms of low testosterone levels.

The American Urological Society defines low testosterone as less than 300 nanograms per deciliter (ng/dl).

Recommended lab tests for men with symptoms of low testosterone:

• Testosterone levels: At least two blood samples should be taken in the morning (between 8 am and 10 am) after fasting. This is because testosterone levels naturally fluctuate throughout the day.
• Sex hormone-binding globulin (SHBG): Testosterone circulates in the blood bound to sex hormone-binding globulin, bound to the protein albumin, or unbound. Only the free testosterone plus the testosterone bound to albumin is available to act on target tissues. Therefore, free testosterone and SHBG should be checked to determine the level of biologically active testosterone.
• Luteinizing hormone (L.H.) and follicle-stimulating hormone (FSH): L.H. and FSH are hormones secreted by the pituitary gland. L.H. stimulates the testes to produce testosterone, and FSH is involved in sperm production. Measuring these two hormone levels can help distinguish between low testosterone originating from a problem in the brain or pituitary gland from one in the testes.
• Prolactin: Prolactin is a pituitary hormone that stimulates milk production in the female. Abnormal levels of prolactin can indicate a problem in the pituitary gland.
• Additional lab tests. 
  • Hemoglobin level to check for red blood cell count. 
  • Lipid panel to check for cardiovascular risk. 
  • PSA to screen for prostate cancer.
  •  A baseline level of free estrogen is also recommended (AACC, 2020). When testosterone is supplemented, some will be converted to estrogen. A baseline level of highly sensitive estrogen will help determine how high the conversion rate is.

The Role of Testosterone 

Testosterone is a hormone that is primarily produced in the testes. It helps maintain and support: 

• Muscle mass
• Muscle strength
• Bone density
• Normal fat distribution
• Body and facial hair
• Red blood cell production
• Sperm production
• Libido
• Erections
• Fertility

Low testosterone levels are linked to obesity, lower HDL cholesterol, higher LDL cholesterol, high blood pressure, an increased incidence of diabetes, and inflammation, all of which increase the risk of cardiovascular disease (Çatakoğlu, 2017). 

The potential benefits of testosterone therapy include increased muscle mass and strength, increased bone density, increased libido and spontaneous erections, improved energy, mood, and motivation, increased red blood cell production, and hair regrowth.

Why Does Each Man’s Timeline Look Different?

Despite the fact that testosterone injections have been used for decades to treat low testosterone levels, it is difficult to predict when you will notice an improvement in your symptoms. This is because each of us metabolizes medications differently, and the endocrine system is complex. A change in one hormone level can have a domino effect throughout the body, improving some symptoms but worsening others. 

Each person who uses testosterone may experience varying degrees and types of side effects and benefits. The signs and symptoms of testosterone deficiency you are experiencing will also vary. As a result, there is no set time frame for when you can expect to see an improvement in your symptoms. 

Serum testosterone levels typically rise above the normal range for 1 to 3 days after treatment begins, then gradually decline to the lower end of the normal range over the course of two weeks. Some men may experience symptoms due to the rapid rise and fall of testosterone levels, necessitating a dosage adjustment. The half-life of an I.M. testosterone injection is approximately eight days (FDA, n.d.).

How Long Does Testosterone Theory Usually Take to See Results? 

Though we cannot offer a definitive timeline, there has been enough research to map out a guide on when you might expect to see an improvement in your symptoms. Saad et al. developed the following timelines after reviewing available research in a meta-analysis.

Less Than One Month

• Sexual interest: Sexual interest increases after three weeks of treatment, plateaus at six weeks, and has no further changes
• Insulin Sensitivity: Insulin sensitivity may improve within a few days, but having stable blood sugar levels may take 3-12 months 
• Erections: An improvement in erection quality is usually noticed after three weeks of treatment, with full erections after 30 days

One Month

• Perceived Quality of Life: Improvements in your perceived sense of well-being can be noticed within 3-4 weeks, but maximum benefits may take much longer
• Mood: Improvement in depressive symptoms usually starts after 3-6 weeks of treatment and reaches a maximum benefit after 18-30 weeks 
• Lipids: Blood lipid levels should improve after about four weeks of treatment and peak at 6 to 12 months 
• Inflammation: A decrease in the indicators of inflammation can be noticed after 3-12 weeks of treatment

Three Months

• Erections: Changes in the quality of erections and ejaculations may take up to six months
• Anemia: An increase in red blood cells may be noticed after three months and peak after 9-12 months of therapy. When anemia or the lack of red blood cells resolve, you should notice increased energy levels and decreased fatigue 
• Blood glucose: Blood glucose levels stabilize at between 3-12 months
• Blood pressure: Diastolic blood pressure may decline after 3-9 months, and sometimes, systolic does as well, with maximum effects after one year

Six Months

• Fat Mass: Usually improves within 12-16 weeks, stabilizes at 6 to 12 months, and gradually improves after that
• Lean Body Mass: Usually improves within 12-16 weeks, stabilizes at 6 to 12 months, and gradually improves after that
• Muscle Strength: Usually improves within 12-16 weeks, stabilizes at 6 to 12 months, and gradually improves after that
• Heart Rate: A decrease in resting heart rate has been noted after 40 to 44 weeks of treatment

One Year

• Bone: Increased bone density may be noticed after six months and continue to improve over the next three years

More Than One Year

• Increased muscle strength improved over the three years it was studied, but reached its maximal effect at 12 months
• Increased lean mass improved over the three years it was studied, but reached its maximal effect at 12 months
• Decreased fat mass reached its maximal effect at 24 months
• Decreased waist circumference reached its maximal effect at 24 months
• Increased exercise capacity reached its maximal effect at 12 months 
• Increased bone mineral density continued beyond three years
• Decreased waist to hip ratio reached its maximal effect at 28 months

Factors That Influence the Duration of Treatment

If your baseline testosterone level is low and you start testosterone therapy, you could be on it indefinitely. When the therapy is stopped, your testosterone level is expected to fall. When your testosterone levels fall below a certain level, your symptoms may return.

Lifestyle factors can also affect how quickly you notice an improvement in your symptoms. You might be able to speed up the process by: 

• Getting enough high-quality sleep
• Eating a well-balanced diet rich in fruits and vegetables, lean protein, and healthy sources of fat
• Incorporating a workout routine into your schedule that includes both aerobic and resistance exercises

How to Get Your Testosterone Levels Tested

If your symptoms are consistent with low testosterone levels, the next step in regaining your health is to have your testosterone levels checked. Invigor Medical’s healthcare professionals specialize in men’s health and can help you determine whether testosterone therapy is right for you.

Invigor Medical offers telemedicine appointments with health care providers in your state. If you are interested in learning whether you would be a good candidate for testosterone therapy, here’s how to get started: 

1. Fill Out Forms: Complete an online medical history form. 

2. Blood Work: Take your order for blood work to LabCorp. A full panel of blood tests is required because the diagnosis of low testosterone requires documentation of both a low testosterone level and the symptoms associated with low testosterone levels. 

A questionnaire such as the Androgen Deficiency in the Aging Male (ADAM) can be helpful in identifying the symptoms of low testosterone levels. 

3. Medical Consultation: After reviewing your history forms and evaluating your blood panel results, a licensed Invigor Medical health care provider in your state will discuss treatment options with you.

4. Get a Prescription: If you’re a good candidate for testosterone replacement therapy, your Invigor Medical provider will prescribe intramuscular testosterone injections and the necessary supplies. Your prescription will be sent to either their compounding pharmacy partner or your local pharmacy.

DISCLAIMER

While we strive to always provide accurate, current, and safe advice in all of our articles and guides, it’s important to stress that they are no substitute for medical advice from a doctor or healthcare provider. You should always consult a practicing professional who can diagnose your specific case. The content we’ve included in this guide is merely meant to be informational and does not constitute medical advice. 

References

Harman SM, Metter EJ, Tobin JD, Pearson J, Blackman MR. Longitudinal effects of aging on serum total and free testosterone levels in healthy men. Baltimore Longitudinal Study of Aging. J Clin Endocrinol Metab. 2001; 86:724–731.

Seftel, A. Male hypogonadism. Part I: Epidemiology of hypogonadism. Int J Impot Res 18, 115–120 (2006). https://doi.org/10.1038/sj.ijir.3901397

Alp Burak Çatakoğlu, Muammer Kendirci. Testosterone replacement therapy and cardiovascular events. Turk Kardiyol Dern Ars. 2017; 45 (7): 664-672

FDA. (n.d.). Depo-Testosterone. Retrieved from https://www.accessdata.fda.gov/drugsatfda_docs/label/2018/085635s040lbl.pdf