Healthcare providers consider testosterone levels below 300 nanograms per deciliter (ng/dL) as low in adults. Standard blood panels were designed to catch acute illness, not to optimize health or uncover the root causes of chronic symptoms. Most patients — and most doctors — believe that "normal" routine blood work means you're healthy. High cortisol levels from stress can lower testosterone. Insomnia, or trouble falling or staying asleep, can also be a side effect of TRT. However, TRT can sometimes cause sleep problems, such as insomnia or sleep apnea. Understanding these side effects can help you manage them better and work more closely with your doctor to achieve the best results. This can help maximize the benefits of TRT and reduce any potential side effects. Your doctor may adjust your TRT dosage to ensure you are receiving the right amount of testosterone. This can lead to a better quality of life, as reduced fatigue allows you to engage more fully in work, social activities, and exercise. Doctors also observe that many patients on TRT report feeling more alert and less tired as their treatment progresses. Key nutrient deficiencies, including vitamin D, B12, iron, and magnesium, can profoundly affect energy levels and mental clarity. Chronic stress or disrupted sleep cycles can throw off the balance of cortisol production, leading to persistent fatigue. Testosterone therapy may be an option for women to help address low libido "Many of these symptoms, especially as men get older, can be due to other factors such as stress, anxiety, pressure, work, aging, relationship issues and even other medications," says Dr. Hakim. Before beginning TRT, or if you are already on TRT and still feeling fatigued, it is important to have your thyroid function checked. If you have hypothyroidism, starting TRT might not fully address your fatigue. If your thyroid is not working properly, it can lead to a condition called hypothyroidism, where the thyroid does not produce enough hormones. The thyroid is a small gland in your neck that produces hormones that help control your metabolism. Stay on top of latest health news from Harvard Medical School. Sign up for HEALTHBeat and receive trusted health information delivered right to your inbox. Get the latest in health news delivered to your inbox! No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician. Also testosterone is known to stimulate growth of prostate cancer in men diagnosed with the condition.
