What is the Origin of Intramuscular Hormone Therapy?

This practice originates from early clinical endocrinology and pharmacology, where intramuscular injection was established as a reliable parenteral route for delivering compounds that are poorly absorbed orally or require a depot effect. The use of long-acting hormone esters cemented its role in replacement therapy.

What is the Mechanism of Intramuscular Hormone Therapy?

The mechanism relies on the depot effect, where the oil-based hormone ester forms a localized reservoir within the muscle tissue. The hormone is then slowly hydrolyzed by local enzymes and diffuses gradually into the capillaries, bypassing the immediate first-pass metabolism of the liver. This controlled release maintains the circulating hormone concentration within the desired physiological range for days or weeks.

Intramuscular Hormone Therapy ∞ Area

Intramuscular Hormone Therapy

Meaning

A specific route of hormone administration where the therapeutic agent, often an oil-based solution of a steroid hormone, is injected directly into a large muscle mass, such as the gluteal or deltoid muscle. This method is clinically favored for achieving a slow, sustained release of the hormone into the systemic circulation, which minimizes the frequency of dosing and provides relatively stable therapeutic blood levels over an extended period.