Existing once-a-month combined injectable contraceptives

Area of Science:

• Reproductive Health
• Endocrinology
• Pharmaceutical Sciences

Background:

• Long-acting injectable contraceptives are crucial for family planning, but traditional formulations (2-6 months) often have suboptimal cycle control.
• Monthly injectable contraceptives aim to improve user satisfaction through better cycle regulation.
• Early monthly injectables faced challenges including logistics, toxicity, and clinical efficacy issues.

Purpose of the Study:

• To review the development and status of monthly injectable contraceptives.
• To highlight advancements in formulation and the resolution of previous product issues.
• To identify ongoing research and development in this contraceptive technology.

Main Methods:

• Historical review of injectable contraceptive development.
• Analysis of formulation changes and their impact on efficacy and safety.
• Evaluation of product availability and regulatory considerations.

Main Results:

• Monthly injectables, incorporating estrogen with reduced progestin, offer superior cycle control compared to longer-acting progestin-only injectables.
• Key products like Mesigyna (norethisterone enantate/estradiol valerate) emerged after extensive problem-solving.
• Existing products (Cyclofem, Perlutal/Topasel) have undergone reformulation or require further safety assessment.

Conclusions:

• Monthly injectable contraception represents a significant advancement in birth control technology.
• Continued research is necessary for new formulations, with ongoing evaluation of safety and efficacy data.
• Addressing toxicological concerns and ensuring reliable supply chains are critical for product success.