New! Sign up for our free email newsletter.
Reference Terms
from Wikipedia, the free encyclopedia

Estrogen

Estrogens (also oestrogens) are a group of steroid compounds, named for their importance in the oestrus cycle, and functioning as the primary female sex hormone. While estrogens are present in both men and women, they are usually present at significantly higher levels in women of reproductive age. They promote the development of female secondary sex characteristics, such as breasts, and are also involved in the thickening of the endometrium and other aspects of regulating the menstrual cycle. Like all steroid hormones, estrogens readily diffuse across the cell membrane; inside the cell, they interact with estrogen receptors. The three major naturally occurring estrogens in women are estradiol, estriol and estrone. Estrogens are used as part of some oral contraceptives and also in estrogen replacement therapy of post-menopausal women.

Related Stories
 


Health & Medicine News

May 3, 2026

Coffee doesn’t just energize—it actively reshapes the gut and mind. Researchers found that both caffeinated and decaf coffee altered gut bacteria in ways linked to better mood and lower stress. ...
Scientists have discovered a way to help the brain clean itself of harmful Alzheimer’s plaques by activating its own support cells. By increasing a protein called Sox9, researchers were able to boost the activity of astrocytes, star shaped cells ...
Free-living amoebae are emerging as a global health concern, fueled by warming temperatures and outdated water systems. While many are harmless, some can cause deadly infections and even protect other dangerous microbes. Their ability to survive ...
Scientists have uncovered a surprising link between simple body movement and brain health: every time you tighten your abdominal muscles—even slightly—your brain may gently sway inside your ...
Building muscle doesn’t have to mean exhausting workouts or soreness. Researchers found that slow, controlled “lowering” movements can boost strength more efficiently while requiring less effort. Even five minutes a day of simple exercises ...
A new breakthrough could change how high cholesterol is treated, offering a powerful alternative to traditional drugs. Researchers have developed tiny DNA-based molecules that shut down PCSK9—a key protein that keeps “bad” LDL cholesterol ...
Kidney stones are notoriously painful—and frustratingly common, with many people facing repeat episodes. A massive new study tested whether a high-tech hydration program—complete with smart water bottles, reminders, coaching, and even financial ...
Chronic stress is already tough on your gut—but new research suggests late-night eating could make things even worse. Scientists analyzing thousands of people found that those under high stress who also ate a large portion of their calories after ...
Scientists have uncovered a surprising new layer of complexity in Cannabis, identifying dozens of previously unknown compounds—including the first-ever evidence of rare molecules called ...
A key protein involved in fat metabolism has been found to do more than scientists once thought. Instead of just releasing fat, it helps maintain healthy fat tissue and balance in the body. When it’s missing or disrupted, the results can be ...
Researchers have identified a new potential weapon against Alzheimer’s: blocking a protein called PTP1B. In mice, this approach boosted memory and helped brain immune cells clear harmful plaque buildup. Since PTP1B is also linked to diabetes and ...
A major review of 217 trials shows that aerobic exercise is the most effective option for managing knee osteoarthritis. Activities like walking, cycling, and swimming outperformed other exercise types in reducing pain and improving movement. While ...

Latest Headlines

updated 12:56 pm ET