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

August 24, 2025

Researchers uncovered that hypothalamic neurons safeguard blood sugar overnight by directing fat breakdown, preventing hypoglycemia during early sleep. This subtle control system may explain abnormal metabolism in ...
Researchers discovered that heart failure patients with inconsistent sleep patterns were more than twice as likely to experience serious setbacks within six months. The risk remained high even when accounting for sleep disorders and other ...
Scientists have developed a groundbreaking cryo-optical microscopy technique that freezes living cells mid-action, capturing ultra-detailed snapshots of fast biological processes. By rapidly immobilizing cells at precise moments, researchers can ...
Researchers have created plant-based microbeads that trap fat in the gut, helping rats lose weight without side effects. Unlike current drugs, the beads are safe, tasteless, and easy to mix into everyday foods. Human trials are now ...
Too much salt may inflame the brain, triggering hormones that push blood pressure higher. Scientists found this pathway could explain why many patients resist current hypertension drugs, pointing toward the brain as a new treatment ...
St. Jude researchers revealed that midkine blocks amyloid beta from forming harmful clumps linked to Alzheimer’s. Without it, the damaging assemblies accelerate, but with it, growth halts. The finding could inspire new drugs that harness ...
Researchers discovered that women with Alzheimer’s show a sharp loss of omega fatty acids, unlike men, pointing to sex-specific differences in the disease. The study suggests omega-rich diets could be key, but clinical trials are ...
Scientists have uncovered a startling split in the venom of Australia’s Eastern Brown Snake. In the south, bites cause rock-solid blood clots, while in the north, they trigger flimsy clots that ...
Researchers identified over 400 genes tied to various forms of frailty, offering fresh insight into why people age differently. The study highlights six distinct pathways of unhealthy aging, opening the door to more precise, targeted anti-aging ...
A large-scale review finds that acetaminophen use during pregnancy may increase the risk of autism and ADHD in children. The strongest studies showed the clearest links, pointing to biological ...
Scientists have finally uncovered the missing link in how our bodies absorb queuosine, a rare micronutrient crucial for brain health, memory, stress response, and cancer defense. For decades, ...
Scientists at UCSF have uncovered a surprising culprit behind brain aging: a protein called FTL1. In mice, too much FTL1 caused memory loss, weaker brain connections, and sluggish cells. But when researchers blocked it, the animals regained youthful ...

Latest Headlines

updated 12:56 pm ET