From the Guidelines
Fluctuations in testosterone levels from high to low within a three-month period can be caused by several factors, with the most likely cause being medication effects, particularly anabolic steroid use followed by withdrawal, as well as laboratory errors or inconsistent testing conditions. The most common causes of these fluctuations include:
- Medication effects, particularly anabolic steroid use followed by withdrawal, which can initially elevate testosterone and then cause suppression of natural production 1
- Laboratory errors or inconsistent testing conditions, such as time of day, fasting status, or different testing methods, which can produce contradictory results
- Medical conditions like pituitary disorders, which may cause testosterone instability
- Stress, significant weight changes, or sleep disruptions, which can temporarily affect hormone levels
- Certain medications, including opioids, glucocorticoids, and some psychiatric drugs, which can suppress testosterone production
- Alcohol consumption patterns, which can impact testosterone, with initial increases followed by decreases with chronic use To determine the specific cause, medical evaluation is recommended, including repeat testing under standardized conditions (morning samples after fasting), comprehensive medical history review, and possibly additional hormone testing to evaluate the entire hypothalamic-pituitary-gonadal axis 1. It is also important to consider the potential benefits and harms of testosterone treatment, as well as the patient's preferences, when evaluating and managing low testosterone levels 1. In men with diabetes, mean levels of testosterone are lower compared to age-matched men without diabetes, but obesity is a major confounder, and testosterone replacement in men with symptomatic hypogonadism may have benefits, including improved sexual function, well-being, muscle mass and strength, and bone density 1.
From the FDA Drug Label
Male hypogonadism, a clinical syndrome resulting from insufficient secretion of testosterone, has two main etiologies. Primary hypogonadism is caused by defects of the gonads, such as Klinefelter's syndrome or Leydig cell aplasia, whereas secondary hypogonadism is the failure of the hypothalamus (or pituitary) to produce sufficient gonadotropins (FSH, LH).
With single daily applications of testosterone gel 50 mg and 100 mg, follow-up measurements at 30 and 90 days after starting treatment have confirmed that serum testosterone and DHT concentrations are generally maintained within the normal range
The cause of a testosterone level being high and over normal limits within three months, and then low and under normal limits, could be due to primary or secondary hypogonadism.
- Primary hypogonadism is caused by defects of the gonads, such as Klinefelter's syndrome or Leydig cell aplasia.
- Secondary hypogonadism is the failure of the hypothalamus (or pituitary) to produce sufficient gonadotropins (FSH, LH) 2.
From the Research
Testosterone Level Fluctuations
The fluctuations in testosterone levels, from high to low within a short period of three months, can be attributed to various factors.
- Hormonal Imbalance: Testosterone levels naturally decrease as men age 3. However, significant fluctuations within a short period may indicate an underlying hormonal imbalance.
- Testosterone Replacement Therapy (TRT): The use of TRT can affect testosterone levels, and adjustments to the treatment regimen can lead to fluctuations in testosterone levels 4, 5.
- Individual Variability: Testosterone levels can vary significantly among individuals, and what is considered a normal range may differ from person to person 6.
- Monitoring and Adjustments: Regular monitoring of testosterone levels and adjustments to treatment regimens can help mitigate fluctuations in testosterone levels 7.
Potential Causes of Fluctuations
Some potential causes of fluctuations in testosterone levels include:
- Changes in Treatment Regimen: Adjustments to TRT or other medications can affect testosterone levels.
- Aging: Natural decreases in testosterone levels due to aging.
- Underlying Medical Conditions: Certain medical conditions, such as hypogonadism, can affect testosterone levels.
- Lifestyle Factors: Lifestyle factors, such as diet and exercise, can also impact testosterone levels.