Body weight and cycle control of injectable contraceptives

Area of Science:

• Reproductive Endocrinology
• Pharmacology

Background:

• Injectable progestogen contraceptives are widely used for family planning.
• Understanding factors influencing their efficacy and side effects is crucial for user counseling and product development.

Purpose of the Study:

• To evaluate the efficacy and side effect profile of five long-acting injectable progestogens.
• To identify factors influencing menstrual cyclicity, including amenorrhea, in users.

Main Methods:

• A clinical trial involving 1,363 women using injectable progestogens for 1-3 years.
• Data collected over 22,304 woman-months, analyzing factors like progestogen dose, estrogen addition, pretreatment cycles, therapy duration, and body weight.
• Comparison of menstrual patterns between overweight, normal weight, and underweight participants.

Main Results:

• Menstrual cyclicity was influenced by progestogen potency, dose, estrogen addition, pretreatment pattern, duration, and body weight.
• A higher incidence of amenorrhea was observed in overweight women compared to normal or underweight women.
• Progestogen storage in adipose tissue was proposed as a mechanism for this observation.

Conclusions:

• Long-acting injectable progestogens are effective contraceptives, but menstrual irregularities like amenorrhea can occur.
• Body weight, particularly being overweight, is a significant factor associated with increased amenorrhea, likely due to drug accumulation in fat tissue.
• Further research into dose adjustments or alternative formulations for overweight individuals may be warranted.