This area is ideal because it is rich in muscle tissue, allowing for better testosterone absorption. Injecting testosterone in the buttocks, specifically in the upper outer quadrant of the gluteal muscle, is one of the most common and most effective methods. Each injection site offers varying benefits based on accessibility and comfort. There are 4 main sites of injecting testosterone; glutes, quads, hips and upper arms. As testosterone levels naturally decline with age or due to conditions like male hypogonadism, symptoms such as fatigue, reduced muscle mass, and decreased libido can arise. If you’re dealing with low testosterone, you may have heard of TRT but are probably wondering which administration method is best for you. Testosterone replacement therapy (TRT) is a widely recognised treatment for male hypogonadism. This was confirmed by pharmacokinetic studies that assessed the Cmax and tmax of testosterone in the serum, and the average serum total testosterone concentration during the steady state. To the contrary, after SC administration, the drug is delivered to the hypodermis (adipose tissue underlying the dermis), which is not only less vascularized compared to skeletal muscles, but the flow in this region does not increase significantly with physical activity. Similar to lymphatics, the hemorheological differences of the vascular compartments of the SC and IM tissues play a role in the pharmacokinetics of testosterone esters. However, the hydrolysis of testosterone esters by tissue esterases is a slow process because of their high lipophilicity, with negligible spontaneous hydrolysis in water (40). Molecules smaller than 1 kDa, such as testosterone, are preferentially absorbed by the blood capillaries because of the high rate of filtration and reabsorption of fluid across vascular capillaries (39). The physiology of the IM and SC milieu determines the patterns of absorption after administration. Testosterone ester is also partly hydrolyzed within the interstitium, with free testosterone entering the circulation directly. On release from the depot, the testosterone ester undergoes hydrolysis into testosterone and the ester-specific fatty acid (35, 36). Benzyl alcohol is soluble not only in the oily phase, but also in the aqueous phase, thus facilitating the release of testosterone ester from the depot into the surrounding interstitial fluid (35). If you know your total testosterone reading from a previous blood test input the results to the left above to see if your testosterone levels are normal. Our team of healthcare experts and GMC registered doctors are licensed to UK GMC standards. Injections deliver testosterone directly into the bloodstream, resulting in faster, stronger effects compared to other methods. Certain medical issues can cause an increased risk of serious reactions and could influence the safety and effectiveness of your treatment. If you feel any shortness of breath, chest tightness, or dizziness after injecting, you must contact a nurse immediately. Many of these symptoms are conditions that would be treated easily with medical care, but it’s still important that you are aware of the possible side effects of this sort of treatment. Before injecting, clean the site thoroughly with an alcohol swab to minimise the risk of infection. Men’s health clinics, urologists, and primary care providers need a compounding partner that delivers consistent quality, fast turnaround, and a smooth patient experience. Testosterone therapy is one of the most commonly prescribed treatments in men’s hormone management. At Massey Drugs, we work closely with urologists, men’s health clinics, and primary care providers to prepare high-quality compounded testosterone and men’s health medications with a fast 24–48 hour turnaround. Sexual health concerns, hair loss, and skin conditions may also require treatment approaches that do not always respond well to commercially available medications. Testosterone is a crucial factor in various bodily processes, including muscle development, bone health, sexual desire, and overall mood. B, Mean serum testosterone concentrations with weekly 100 mg intramuscular administration of testosterone enantathe to men with primary hypogonadism (vertical arrows represent injections, error bars represent SEM, and dashed lines represent normal range. Adapted with permission from (46). As different muscle groups have variable blood flow (eg, the blood flow to the deltoids is higher than the glutei) (44), which further varies with physical activity (45), serum on-treatment testosterone concentrations after IM injections are dependent on these characteristics. Indeed, long-term compliance among men who are prescribed testosterone therapy with IM injections is low; approximately 69% of men on long-acting esters discontinue treatment within 3 months of therapy, and 95% discontinue it within 12 months (56). A study of transgender men receiving SC weekly doses of testosterone enanthate or cypionate (28) showed that 37 of 67 participants developed acne; 2 of these individuals needed a referral to a dermatologist, while no participant chose to decrease their testosterone dose. Because of the longer absorption time, it was introduced as an option to minimize peaks and troughs in serum testosterone levels after dosing, as well as to reduce the frequency of injections in men with organic androgen deficiency who require long-term testosterone therapy. IM testosterone therapy was maintained for 3 weeks after enrollment before switching to self-administration of the same dose via the SC route for 8 weeks. In a follow-up study by the same investigators, 21 men (aged years) with symptomatic testosterone deficiency self-administered weekly SC testosterone enanthate at a dose of 75 mg for 12 weeks via SC autoinjector (29).
