To evaluate the effect on Two months modified Intermittent fasting for premenstrual syndrome on medical students. Intermittent fasting using a 20:4 hour protocol 20 hours of fasting followed by a 4 hour eating window may help reduce symptoms of premenstrual syndrome PMS, potentially by improving mitochondrial and other systemic functions in the body.Intermittent fasting has shown positive effects on mitochondrial health, which is crucial for efficient cellular energy production and overall metabolic function. Mechanisms includePromotion of mitochondrial fusion via sirtuin activation.Enhanced mitophagy and turnover.Reduction in oxidative stress and improved overall cellular energetic balance.These effects help the body repair and optimize vital functions, potentially alleviating common PMS symptoms like fatigue, mood swings, and pain, which are partly linked to mitochondrial dysfunction. Also The gut microbiota plays a significant role in the gastrointestinal system, where dietary tryptophan is mostly converted to serotonin. 20:4 fasting can improve metabolic flexibility by increasing insulin sensitivity and reducing inflammation. For premenopausal women, particularly those with obesity or hormonal disturbances intermittent fasting may lower androgen levels , increase sex hormone-binding globulin . It does not significantly affect estrogen or gonadotropin levels, but when food is consumed earlier in the day, benefits for androgen markers were most evident.