A recent study (40) observed a decrease after 24 weeks; others have found that this occurs after 9 months (4) or 12 months (4) with a maximum reached. Injectable testosterone undecanoate, when administered in oil, can maintain serum T levels in the normal range for 10 to 12 weeks after intramuscular injection, 73 A typical testosterone undecanoate regimen employs an initial injection of 1000 mg IM, a second injection of 1000 mg at 6 weeks, followed by IM injections of 1000 mg every 12 weeks, 73 The relative advantages of this injectable formulation are its long duration of action and its lower degrees of fluctuation in serum testosterone levels than observed with testosterone enanthate and cypionate. However, testosterone undecanoate is administered in a large volume of oil, causing discomfort to the patient. In most cases involving testosterone injections, the peak occurs 2 to 3 days later of the injection.
Thereafter, testosterone levels in a person's body eventually decrease until a new injection is required. As mentioned, the total process takes between 3 and 6 months to see all the long-term results. There are different types of testosterone injections available, each with different peak times, depending on the type of ester. These esters control the rate of release of testosterone, which affects how quickly it enters the bloodstream and how long it remains active. Knowing peak times allows you to align your injections with the periods when symptom relief is most needed.
For example, athletes can schedule injections to match training or competition. Knowing when testosterone peaks after an injection is crucial to getting the most out of therapy. The times of greatest activity vary depending on the type of ester, the method of injection and individual factors, but understanding these differences can help you align treatment with your goals. Always work closely with your healthcare provider to ensure that your testosterone therapy meets your needs. Testosterone is well absorbed after oral administration, but undergoes rapid presystemic metabolism after oral administration.
When a person reaches 30 years of age, their testosterone levels naturally begin to decline by around 1% each year. Testosterone enanthate and testosterone cypionate are widely used injectable long-acting testosterone preparations. Treating hypogonadal men with testosterone is rewarding, both for patients and for the physician. Dose adjustments should be made based on serum testosterone levels measured 14 days after the start of treatment and should be adjusted two to eight hours after the dose is administered.
Replacement testosterone can be administered using one of several available formulations, paying due attention to its pharmacokinetics (Table). In the case of long-acting intravenous preparations, testosterone concentration and clinical effects (e.g., effects on mood and libido) peak about 1 to 2 days after injection and decrease within 2 weeks following. Overall testosterone levels after injection will be higher than baseline levels, but the exact magnitude of the increase will vary from person to person. Therefore, testosterone enanthate and cypionate with longer side chains have a longer duration of action than testosterone propionate.
Serum testosterone levels should be measured 14 and 28 days after the start, before the morning dose. Mucoadhesive tablets are applied to the gums in the mouth and provide a controlled and sustained release of testosterone as the oral system moisturizes. From studies that analyzed the effects of administering testosterone for 36 months (25, 2), an increase was observed over that period of time and it was not clear if the maximum effects of testosterone in improving bone mineral were achieved after 36 months. Based on testosterone levels after an injection graph, it is evident that testosterone levels do not increase linearly, but follow a J-shaped curve.
The range of levels between the two doses illustrates the flexibility offered by transdermal testosterone gel (30). Whether it's to treat low testosterone levels or to improve performance, knowing when these peaks occur helps ensure better results and minimizes potential side effects.
