Treatment Approach for Flipped LH and FSH Levels
Understanding "Flipped" LH/FSH Ratio
The term "flipped LH and FSH" typically refers to an abnormal ratio where LH is disproportionately elevated relative to FSH, most commonly seen in polycystic ovary syndrome (PCOS), or conversely, where both are low in hypogonadotropic hypogonadism (HH). The treatment strategy depends entirely on which pattern is present and the clinical context.
Pattern 1: Low LH and Low FSH (Hypogonadotropic Hypogonadism)
For patients with deficient LH and FSH secretion, exogenous gonadotropin therapy is the standard treatment approach, not selective estrogen receptor modulators (SERMs). 1
Treatment Algorithm for HH:
Refer to an endocrinologist or male reproductive specialist immediately upon identifying low LH and low FSH with low testosterone 1
Initiate hCG injections first to stimulate testosterone production by Leydig cells 1
- Monitor serum testosterone response after starting hCG
- Continue until testosterone normalizes
Add FSH or FSH analogues after testosterone normalization to optimize spermatogenesis 1
- This sequential approach is critical for restoring fertility
- Combined hCG and FSH therapy provides optimal outcomes 1
Alternative option: Pulsatile GnRH therapy can initiate spermatogenesis and achieve pregnancies in many men with idiopathic HH 1
- Pulsatile GnRH may be more efficient than exogenous gonadotropins in some patients 1
Critical Contraindications:
- Never prescribe exogenous testosterone to men interested in current or future fertility, as it provides negative feedback to the hypothalamus and pituitary, suppressing gonadotropin secretion and potentially causing azoospermia 1
Pattern 2: Elevated LH with Normal or Low FSH (PCOS-like Pattern)
For patients with elevated LH levels, particularly in the context of anovulation, treatment focuses on reducing LH excess and stimulating follicular development with FSH.
Treatment Algorithm for Elevated LH:
Use highly purified FSH preparations without LH activity in patients with elevated baseline LH 2
Consider GnRH agonist down-regulation followed by purified FSH for optimal ovulation induction 3
- This approach suppresses excessive endogenous LH
- Allows controlled follicular stimulation with FSH alone
For women with functional hypothalamic amenorrhea and polycystic ovarian morphology (FHA-PCOM):
Monitoring Requirements:
- Suppress progesterone and androgen concentrations during the follicular phase as a major treatment objective 5
- Elevated LH with high androgens indicates undertreatment and requires adjustment 5
Pattern 3: Normal LH and FSH (Not True "Flipped" Ratio)
If FSH, LH, and testosterone are all within normal adult male reference ranges, this indicates a properly functioning hypothalamic-pituitary-testicular axis and does not meet criteria for hypogonadism. 6
Management Approach:
Do not initiate testosterone therapy based solely on borderline levels without documented symptoms 6
- Diagnosis requires both biochemical confirmation AND clinical symptoms 6
Evaluate for reversible causes before any hormonal intervention: 6
Recommend lifestyle modifications first: 1, 6
- Weight loss through low-calorie diets can reverse obesity-associated secondary hypogonadism
- Physical activity provides similar benefits with modest testosterone increases (1-2 nmol)
Common Pitfalls to Avoid:
Do not use SERMs (clomiphene, tamoxifen) for idiopathic infertility, as benefits are limited and outweighed by assisted reproductive technology (ART) options like IVF 1
Do not use FSH analogues in men with normal baseline FSH, as fertility benefits are measurable but limited 1
- FSH is not FDA-approved for this use 1
Do not prescribe clomiphene citrate for male infertility, as there are no adequate studies demonstrating effectiveness, and testicular tumors and gynecomastia have been reported 4
Do not assume PCOS based solely on elevated LH/FSH ratio—must exclude functional hypothalamic amenorrhea, which can present with polycystic ovarian morphology but requires different treatment 1