Coconut Oil Fatty Acid Shows Promise Against PCOS in Mouse Study

Polycystic ovary syndrome, or PCOS, is one of the most common endocrine disorders in women of reproductive age, affecting an estimated 6 to 20 percent of this population worldwide. Characterized by irregular menstrual cycles, cystic ovarian follicles, anovulation, and elevated levels of luteinizing hormone and androgens, the syndrome is far more than a reproductive problem. Women with PCOS frequently develop obesity, dyslipidemia, and insulin resistance, and they face elevated long-term risks of type 2 diabetes and cardiovascular disease. Because current therapies address symptoms rather than root mechanisms, researchers continue to search for agents that can simultaneously correct the hormonal and metabolic disturbances that define the condition. A new study published in the open-access journal Heliyon now suggests that an unlikely candidate, lauric acid, the dominant fatty acid in coconut oil, may partially reverse these disturbances in an animal model of the disease.

The research team, led by Elnaz Harooni and colleagues at Ahvaz Jundishapur University of Medical Sciences in Iran, focused on a well-established experimental approach: the letrozole-induced PCOS mouse. Letrozole is a nonsteroidal inhibitor of aromatase, the enzyme encoded by the Cyp19a1 gene that converts testosterone into estrogen. By blocking estrogen production, letrozole causes androgens to accumulate in female rodents, producing a cluster of symptoms that closely mirrors human PCOS, including androgen excess, elevated blood glucose, abnormal follicle development, and oxidative stress. The researchers administered letrozole orally at 6 milligrams per kilogram of body weight for 21 consecutive days to adult female NMRI mice, then confirmed the PCOS phenotype through daily vaginal smear cytology, which revealed disrupted and arrested estrous cycles in the treated animals.

Lauric acid is a medium-chain fatty acid that accounts for roughly 45 to 53 percent of coconut oil and is widely credited with many of the oil’s reported health benefits, from improved cognitive function in Alzheimer’s disease to reduced cardiovascular risk. Previous work has shown that lauric acid can lower body weight, improve lipid profiles, and enhance insulin sensitivity, effects that have been linked to activation of the Sirt1/AMPK signaling pathway in the liver. That pathway is central to cellular energy sensing: AMP-activated protein kinase, or AMPK, monitors intracellular energy status and maintains energy homeostasis at both the cellular and whole-body levels, while sirtuin 1, or Sirt1, is an NAD-dependent histone deacetylase involved in glucose and lipid metabolism, oxidative stress regulation, and reproductive function. Notably, Sirt1 expression in the ovary is reduced in both human PCOS patients and animal models, making the Sirt1/AMPK axis an attractive therapeutic target.

In the new experiment, forty mice were divided into four groups of ten: a normal control group, a group receiving lauric acid alone, a PCOS group receiving letrozole followed by vehicle, and a PCOS group treated with lauric acid at 150 milligrams per kilogram per day for 15 days after PCOS induction. The dose was selected on the basis of prior studies demonstrating its efficacy and safety across a wide range. The results were striking in several domains. Lauric acid treatment significantly lowered fasting blood glucose and fasting insulin concentrations in the PCOS mice, and it significantly improved both the HOMA-IR index, a standard measure of insulin resistance, and the QUICKI index, which reflects insulin sensitivity. Given that compensatory hyperinsulinemia drives many PCOS features and increases the risk of cardiovascular disease and type 2 diabetes, this metabolic improvement is clinically meaningful.

The fatty acid also reshaped the hormonal landscape of the treated animals. Letrozole had produced the classic PCOS hormonal signature: elevated luteinizing hormone, an increased LH-to-FSH ratio, and raised testosterone, accompanied by reduced follicle-stimulating hormone, progesterone, and estradiol. Fifteen days of lauric acid administration significantly decreased testosterone, LH, and the LH/FSH ratio while significantly raising estradiol levels. Mechanistically, this appears to involve restoration of the aromatase machinery: lauric acid significantly reversed the letrozole-driven decline in ovarian Cyp19a1 protein expression, the very enzyme the drug inhibits, while simultaneously reducing the elevated expression of ovarian androgen receptors that had heightened the animals’ sensitivity to accumulated androgens. Progesterone levels, however, remained depressed despite treatment, a limitation the authors openly acknowledge.

Lipid metabolism responded robustly as well. PCOS mice showed markedly elevated triglycerides and LDL cholesterol alongside reduced HDL cholesterol, a dyslipidemic pattern that mirrors the cardiovascular risk profile of human patients. Lauric acid treatment significantly increased HDL cholesterol and reduced both LDL cholesterol and triglycerides, and it significantly lowered the atherogenic index, a logarithmic marker of cardiometabolic risk calculated from the triglyceride-to-HDL ratio. Interestingly, lauric acid improved this index even in healthy mice, suggesting the fatty acid may beneficially modulate lipid handling independent of disease state. Consistent with these findings, the expression of two key adipose tissue regulators, adiponectin and peroxisome proliferator-activated receptor gamma, or PPARγ, was sharply reduced in the white adipose tissue of PCOS mice and significantly restored by lauric acid treatment. These molecules cooperate in regulating glucose and lipid homeostasis, and their upregulation may partially explain the observed improvements in insulin sensitivity.

The study also probed the oxidative and structural consequences of the disease. Ovaries from PCOS mice contained significantly higher concentrations of malondialdehyde, a lipid peroxidation product, and significantly lower total antioxidant capacity, reflecting the oxidant-antioxidant imbalance known to impair oocyte maturation, ovulation, and fertilization. Lauric acid treatment shifted both markers back toward normal. Histological examination told a parallel story: letrozole produced large ovarian cysts and drastically reduced the number of healthy and antral follicles, whereas lauric acid-treated mice showed fewer cystic follicles and a significant recovery of antral follicle formation, indicating a partial resumption of follicular development. Western blot analysis provided the molecular capstone, revealing that lauric acid significantly restored the letrozole-suppressed expression of Sirt1 and AMPK proteins within ovarian tissue.

The authors propose that these molecular changes form a coherent mechanism. Sirt1 is known to regulate aromatase expression in granulosa cells and to protect both pancreatic beta cells and ovarian granulosa cells through antioxidant and anti-inflammatory actions, while the Sirt1/AMPK pathway has been directly implicated in the insulin resistance of PCOS. The restoration of GLP-1, a gut-derived incretin hormone that fell significantly in PCOS mice and rebounded with lauric acid treatment, adds another layer, since GLP-1 receptor agonists are increasingly used to manage PCOS and have been linked to enhanced adiponectin and PPARγ activity. Not every parameter responded, however. Body weight gain induced by letrozole was not reversed, spexin, another metabolic hormone, remained unchanged, and the improvement in estrous cyclicity, though notable, with 60 percent of treated mice showing normal cycles versus 30 percent of untreated PCOS mice, did not reach statistical significance.

As the authors emphasize, this is the first study to evaluate lauric acid in a letrozole-induced PCOS model, and the findings should be interpreted as preliminary. The work was conducted in mice over a short treatment window, and the improvements, while broad, were partial and inconsistent across all measured endpoints. Translating a 150 milligram per kilogram daily dose into a safe and effective human regimen would require extensive dose-ranging, pharmacokinetic, and safety studies, and the relationship between dietary coconut oil consumption and purified lauric acid supplementation is far from straightforward. Nevertheless, the convergence of evidence, improved insulin sensitivity, corrected dyslipidemia, partially restored sex hormones, reduced oxidative stress, healthier ovarian histology, and reactivated Sirt1/AMPK signaling, positions lauric acid as a compelling candidate for further investigation as a complementary agent against the metabolic and endocrine disturbances of PCOS. Larger and longer studies will be needed to confirm whether this humble coconut-derived fatty acid can truly deliver on that promise.

Subject of Research: Effects of lauric acid on endocrine and metabolic alterations in a letrozole-induced mouse model of polycystic ovary syndrome

Article Title: Lauric acid ameliorates endocrine-metabolic alterations in letrozole-induced polycystic ovary syndrome in female mice

Article References: Harooni, E., Ahangarpour, A., Khorsandi, L., & Mard, S. A. (2026). Lauric acid ameliorates endocrine-metabolic alterations in letrozole-induced polycystic ovary syndrome in female mice. Heliyon, 12(15), Article e45556. https://doi.org/10.1016/j.heliyon.2026.e45556

Image Credits: AI Generated

DOI: Not provided

Keywords: PCOS, lauric acid, coconut oil, Sirt1, AMPK, insulin resistance, letrozole, hyperandrogenism, adiponectin, PPAR gamma, oxidative stress, mouse model