Quick summary: Testosterone levels decline gradually after age 30, and for some men the drop is significant enough to affect energy, mood, sexual function, and body composition. Hormone replacement therapy (HRT) can restore levels to a healthy range under medical supervision. At OC Weight Loss & Med Spa in Mission Viejo, evaluation begins with a blood panel and a clinical consultation to determine whether treatment is appropriate and which delivery method fits your lifestyle. Individual results vary, and candidacy is determined by your provider.
Medically reviewed by the clinical team at OC Weight Loss and Med Spa. Last updated: June 12, 2026.
How testosterone changes with age
Testosterone is the primary androgen in men. It influences muscle mass, bone density, red blood cell production, mood regulation, cognitive function, and sexual health. Levels peak in late adolescence and the early twenties, then decline at roughly 1 percent per year after age 30.
For many men this gradual shift goes unnoticed. For others, the cumulative effect becomes significant by their 40s or 50s. Clinically low testosterone — typically defined as a serum total testosterone below 300 ng/dL alongside symptoms — is sometimes referred to as hypogonadism or androgen deficiency.
Symptoms of low testosterone
Symptoms vary widely and overlap with other conditions, which is why a blood test is necessary before any treatment decision. Commonly reported symptoms include:
- Persistent fatigue and low energy despite adequate sleep
- Reduced libido or difficulty with sexual function
- Loss of muscle mass or increased body fat, particularly around the abdomen
- Mood changes, including irritability or low mood
- Difficulty concentrating or reduced mental sharpness
- Decreased bone density over time
A single symptom is rarely diagnostic on its own. Your provider will review lab results alongside your health history and symptom pattern before recommending a course of action.
What hormone replacement therapy involves
Hormone replacement therapy for men works by supplementing the body’s testosterone to restore levels within a healthy physiological range. Several delivery methods are available, each with different dosing schedules and absorption profiles.
- Injections: Administered intramuscularly, typically every one to two weeks. Levels peak shortly after injection and taper gradually.
- Topical gels or creams: Applied daily to the skin. Provide relatively stable levels but require care to avoid transfer to others.
- Subcutaneous pellets: Small pellets are inserted under the skin during a brief in-office procedure. They release testosterone steadily over three to six months and require no daily maintenance.
At OC Weight Loss & Med Spa, treatment decisions are made collaboratively between the patient and the clinical team, led by Lindsay Short, NP, under the physician supervision of Dr. Nezar Dahdal, MD. The goal is to find the delivery method that best fits your schedule, health history, and clinical response.
Realistic expectations
Many men notice initial changes in energy and mood within the first few weeks of treatment. Improvements in body composition and sexual function typically develop over several months. Bone density changes, if measurable, occur over a longer timeframe.
HRT is not a permanent fix applied once and forgotten. Levels are monitored with follow-up blood work, and the dosage may be adjusted over time. Lifestyle factors — sleep, nutrition, exercise — remain relevant alongside treatment. Individual results vary.
Safety, side effects, and who should not use this treatment
Testosterone therapy is well-studied when used appropriately under medical supervision, but it is not without risks. Patients and providers weigh these carefully before starting treatment.
Common side effects can include acne or oily skin, mild fluid retention, increased red blood cell count (erythrocytosis), and testicular atrophy due to suppression of the body’s own production. Erythrocytosis, if significant, raises the risk of blood clots and is monitored through periodic lab work.
Cardiovascular considerations: The relationship between TRT and cardiovascular events has been studied extensively. Current evidence suggests that in men with confirmed hypogonadism, appropriately dosed therapy does not increase cardiovascular risk in most patients — but men with existing heart disease, recent heart attack, or stroke require careful evaluation and may not be candidates.
Prostate health: Testosterone therapy is contraindicated in men with known or suspected prostate cancer. PSA levels and prostate symptoms are typically monitored during treatment.
Fertility: Exogenous testosterone suppresses sperm production. Men who wish to preserve fertility should discuss alternatives with their provider before starting TRT.
TRT is generally not appropriate for men with normal testosterone levels, untreated severe obstructive sleep apnea, polycythemia, or hypersensitivity to the formulation used. Whether you are a candidate is determined at consultation by your medical provider.
Frequently asked questions
How do I know if my testosterone is actually low?
A blood test measuring serum total testosterone (and sometimes free testosterone) is the starting point. A single low result is usually confirmed with a repeat test. The presence of symptoms alongside low lab values is what guides a clinical diagnosis — lab numbers alone are not sufficient.
What is pellet therapy and how does it differ from injections?
Pellet therapy involves inserting a small bioidentical hormone pellet under the skin of the hip or buttock in a brief in-office procedure. Unlike injections, which cause peaks and troughs in hormone levels, pellets release testosterone at a relatively steady rate over three to six months. The main appeal is convenience — no daily application or regular injections.
How long before I notice results?
Patients often report improved energy and mood within two to four weeks. Libido and sexual function changes may take six to twelve weeks. Changes in muscle mass and body composition are typically apparent after three to six months of consistent treatment. Individual results vary.
Can lifestyle changes raise testosterone without medication?
For men with mildly low or borderline levels, resistance training, improved sleep, weight management, and stress reduction can produce modest improvements. These are appropriate first steps for mild cases. For men with clinically confirmed hypogonadism and significant symptoms, lifestyle changes alone are generally insufficient.
Is TRT something I stay on permanently?
Many men do continue TRT long-term because the underlying decline does not reverse. Others may trial it for a defined period. Stopping TRT requires a managed taper in most cases, since the body’s natural production has been suppressed. Your provider will discuss what long-term management looks like for your situation.
Take the first step at OC Weight Loss & Med Spa
If you have been experiencing symptoms consistent with low testosterone, a consultation is the appropriate starting point. The clinical team at OC Weight Loss & Med Spa in Mission Viejo, CA reviews your labs, medical history, and goals before recommending any treatment. No obligation, no pressure — just a grounded clinical conversation about whether HRT is right for you.
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