Bioidentical testosterone cream is a form of hormone replacement therapy using an active ingredient structurally identical to the testosterone naturally produced by the female body. This transdermal delivery method allows the hormone to be absorbed through the skin and directly into the bloodstream, bypassing the digestive system and liver metabolism. Achieving the desired therapeutic effect requires not only the correct dosage but also proper application to specific areas of the body. The choice of application site is crucial for maximizing efficacy, maintaining safety, and minimizing the risk of unwanted side effects.
Principles Governing Application Location
The choice of application sites centers on maximizing transdermal absorption and minimizing the risk of accidental transfer to other individuals. Transdermal delivery relies on the skin acting as a permeable membrane, allowing the hormone to enter the systemic circulation. This process bypasses the first-pass effect, which is the breakdown of the hormone that occurs when taken orally.
The rate of absorption is significantly influenced by the characteristics of the skin in the application area. Areas with thinner skin, a lower density of hair follicles, and a rich supply of blood vessels tend to absorb the cream more efficiently and predictably. Conversely, applying the cream to areas with thick, calloused, or fatty skin can lead to inconsistent absorption and variable hormone levels in the blood. Selecting a site that is easily covered by clothing is also a factor, as this helps prevent the accidental transfer of the hormone to partners, children, or pets upon contact.
Recommended Systemic Application Sites
For women seeking a general, systemic effect to address symptoms like low libido, fatigue, or mood changes, the cream is applied to areas that offer consistent absorption into the bloodstream. These sites are typically thin and vascular, such as the inner upper thighs, the back of the calves, or the upper outer thighs. The lower abdomen and inner forearms are also sometimes used, though the forearms require caution due to the risk of accidental hand-to-hand transfer.
It is recommended to rotate the application site daily or every few days to prevent saturation of the skin in one spot. Continuous application to the same patch of skin can lead to a localized build-up of the hormone, potentially causing skin irritation or localized androgenic side effects like increased hair growth at that specific site. Regular rotation among a few approved areas helps ensure consistent absorption and reduces the likelihood of these localized adverse reactions.
Localized Application and Specific Considerations
In some cases, testosterone cream may be prescribed for localized application to treat specific symptoms, distinct from general systemic use. This localized approach often targets the vulva or clitoral area to address symptoms like sexual dysfunction, decreased sensitivity, or genitourinary syndrome of menopause. The goal in these instances is to deliver the hormone directly to the tissue that possesses a high density of hormone receptors.
Low-dose application to these sensitive areas provides a direct therapeutic effect on the tissues, improving blood flow and sensitivity, often with minimal overall increase in systemic testosterone levels. Due to the high vascularity of the vulvar area, absorption can be rapid, but the small dose is intended to primarily benefit the local tissue. Concentrations and dosages for localized application are often much lower than those intended for systemic use and must be followed precisely as directed by a healthcare provider.
Application Technique and Safety Precautions
Before applying the cream, the skin should be clean, dry, and free from any other lotions, oils, or powders, as these can impede the absorption of the hormone. The prescribed amount, which is often a small pea-sized portion, should be measured precisely according to the doctor’s instructions.
The cream should be gently massaged into the designated application site until it is fully absorbed into the skin. After application, allow the area to dry completely before dressing, which usually takes several minutes. Immediately and thoroughly washing the hands with soap and water is a mandatory safety step to prevent accidental transfer of the hormone. To avoid transference, the application site should be covered with clothing, and skin-to-skin contact with others should be avoided for several hours.