Follicle Stimulation / Ovulation Induction

By RRM Academy Reviewed by Dr. Naomi Whittaker, MD, Board-Certified OBGYN, MIGS, NFPMC, FCI Updated May 7, 2026

The use of pharmacological agents to stimulate follicle development and ovulation in cycles where the natural process is inadequate or absent. In RRM and NaPro Medical protocols, ovulation induction uses oral agents, primarily clomiphene citrate or letrozole, timed to the follicular phase based on Creighton Model charting. The goal is to support the body's own ovulatory process, not to retrieve oocytes.

Letrozole (an aromatase inhibitor) is the preferred first-line agent for ovulation induction in many RRM protocols, particularly for PCOS and anovulatory infertility. The NEJM trial by Legro and colleagues demonstrated letrozole's superiority over clomiphene for live birth rates in PCOS.⁷⁶ Clomiphene remains in use where letrozole is not indicated or available, and in combination protocols.

Cycle monitoring during ovulation induction is standard in RRM practice. A follicle maturation study confirms follicle growth, guides the decision to add an HCG trigger, and identifies poor response early rather than after multiple failed cycles. Monitoring also prevents inadvertent multi-follicular development, which carries its own risks in natural conception protocols.

Ovulation induction in this context is fundamentally different from controlled ovarian hyperstimulation (COH) used in IVF protocols. COH intentionally stimulates multiple follicles for oocyte retrieval. RRM ovulation induction targets one well-developed follicle for in-body conception. The pharmacological agents may overlap. The clinical goals do not.

This content is for educational purposes only and does not constitute medical advice. Consult an RRM clinician or healthcare provider for guidance specific to your situation.