Dr. Daccarett's PCOS progesterone claims need more proof

What did @sarahdaccarettmd actually say?

The claim is straightforward and confident: "PCOS is caused by low progesterone." From there, the video builds a chain: low progesterone fails to suppress LH, elevated LH drives the ovaries to overproduce testosterone, and that testosterone excess causes insulin resistance, facial hair, acne, hair loss, and missed periods. The fix, she argues, is getting "intrauterine progesterone levels up high enough" to lower LH. Diet and exercise, she says explicitly, are not enough. This is presented as a corrective to mainstream thinking, framed with the authority of a physician who sees these patients directly.

It's a tidy mechanistic story. The problem is that it inverts the actual causal direction of PCOS in ways that matter clinically, and it markets progesterone as a reversal therapy without evidence supporting that framing.

Does the science back this up?

Not in the way the video presents it. The neuroendocrinology of PCOS is more complicated than a progesterone deficiency story, and the leading models don't support "low progesterone" as the root cause.

The most well-supported mechanistic framework involves GnRH pulse frequency. In PCOS, GnRH pulses from the hypothalamus are abnormally fast, which selectively drives LH secretion over FSH. This is thought to be partly due to impaired progesterone sensitivity in the hypothalamus, not simply low progesterone levels. McCartney et al. (2002, Journal of Clinical Endocrinology and Metabolism) demonstrated that women with PCOS show reduced hypothalamic sensitivity to progesterone feedback, meaning the pituitary-hypothalamic axis doesn't respond normally even when progesterone is present.

Insulin resistance in PCOS also appears to be at least partially independent of testosterone. Dunaif et al. (1989, Diabetes) showed that women with PCOS have intrinsic insulin signaling defects in skeletal muscle that are not fully explained by androgen excess. The video's framing, that testosterone causes insulin resistance in a linear chain starting from low progesterone, skips over this evidence entirely.

What did they get wrong (or right)?

The elevated LH piece is real. LH is genuinely elevated in a significant subset of women with PCOS, and it does stimulate theca cell androgen production. That part holds up. The clinical observation that diet and exercise alone often fail to normalize hormones in PCOS also has support in the literature and reflects genuine patient experience.

But the causal claim, "PCOS is caused by low progesterone," is where this goes off track. The science suggests the relationship runs the other way in key respects: it's the disordered GnRH-LH axis and the impaired progesterone sensitivity that precede the hormonal cascade, not a simple deficiency of progesterone that can be corrected by supplementation. Calling PCOS a progesterone deficiency disease is a reductive and commercially convenient framing.

The word "reverse" is also doing a lot of work here. The video implies that raising progesterone reverses PCOS. There are no large randomized controlled trials showing bioidentical progesterone supplementation reverses PCOS as a condition. Using progesterone to induce a withdrawal bleed or regulate cycles in anovulatory women is established practice. Reversing the underlying pathophysiology with progesterone is not.

What should you actually know?

PCOS is a heterogeneous syndrome, not a single-cause disease. Diagnosis requires meeting Rotterdam criteria: two of three features, which are irregular cycles, clinical or biochemical androgen excess, and polycystic ovarian morphology on ultrasound. Roughly 70 percent of women with PCOS have insulin resistance, but the mechanism involves multiple pathways, not just testosterone (Diamanti-Kandarakis and Dunaif, 2012, Endocrine Reviews).

Established first-line treatments include lifestyle intervention for those with metabolic involvement, combined oral contraceptives for cycle regulation and androgen suppression, and metformin for insulin resistance management. Progesterone is used clinically in PCOS contexts, primarily to protect the endometrium in anovulatory women and to induce withdrawal bleeds. That is meaningfully different from the claim that progesterone treats or reverses PCOS by lowering LH.

If you have PCOS and are considering hormone therapy beyond standard of care, that conversation belongs with an endocrinologist or reproductive endocrinologist, not an Instagram video, including this one.