Premarin, the hormone medication derived from pregnant horses, is 'PREgnant MARes urINe'

Premarin was the bestselling drug in the US in 1992

The drug, derived from the urine or pregnant mares, raised ethical and animal welfare concerns, but also became wildly popular until the Women's Health Initiative study findings in 2002 (which have since been largely disproved). In the 1990s, Premarin was used to treat menopause symptoms and also to protect against osteoporosis and heart disease among older women.

Modern pregnancy tests detect a specific hormone in a woman's urine or blood

They pick up human chorionic gonadotropin, in either blood or urine. The hormone is produced by a woman's reproductive tissues during pregnancy.

There are multiple HRT options to treat menopause and perimenopause symptoms

This lengthy video features a board-certified OB/GYN based in Texas who provides a thorough overview of the different formulations for HRT, used to treat symptoms including hot flashes, vaginal dryness, and mood swings, and the pros and cons of each. She also discusses modern synthetic options versus the older formulation extracted from the urine of confined pregnant horses.

Read the 1963 study testing out an ancient Egyptian pregnancy urine test

The study sought to test out the ancient Egyptian approach of having a woman urinate on barley and wheat seeds to ascertain pregnancy status. Surprisingly, the research concluded that pregnant women's urine did promote growth of cereal grains the majority of the time; nonpregnant women's urine did not. Unfortunately, the sex of the child could not be accurately predicted based on which crop grew.

Mifepristone, approved in 2000, is used to end early pregnancies

The drug works by blocking progesterone, a hormone that is needed to support pregnancy. Mifepristone is typically used in combination with a second drug, misoprostol, because this regimen often causes less cramping and bleeding than just using misoprostol alone.

Early peptide research focused on isolating the substances from animal tissue

In the first half of the 20th century, peptides including insulin and adrenocorticotropic hormone were isolated from animals to provide life-saving medicines. ACTH was isolated from the pituitary glands of cows and pigs and insulin was isolated from the pancreas of dogs and cows.

Horses can—and sometimes should—drink beer

Despite its reputation, beer is a good source of nutrition. In fact, it's a fairly common practice for horse owners to give beer to their horses. Beer is rich in skin-healing B vitamins, gut-stabilizing yeast, and hydration-encouraging barley. Plus, horse livers come prepared with special enzymes that break down alcohol, making inebriation nearly impossible.

Merck developed MDMA in the early 1900s as part of its effort to create a blood clotting drug

The company's chemists were attempting to synthesize a substance that could compete with an existing patent for the best clot medicine of that time, hydrastinine. MDMA was the byproduct of that effort.

The word allergy is partly derived from the Greek word 'allos' for 'other'

For people with allergies, their immune systems recognize substances as a harmful "other"—cuing an inflammatory response. This podcast explores allergy details and related topics, including how scientists are interested in if the same allergic response mechanisms could underpin other health issues, including severe, painful symptoms around the time of menstrual cycles. Since estrogen acts on white blood cells called mast cells, which leads to the release of histamines—similar to what happens during allergic responses—an understudied question is whether the same process is fueling some of the uncomfortable symptoms around menstruation. An allergist guest notes this raises questions about if antihistamine medications like Pepsid might alleviate them, something that hasn't yet been explored in clinical trials.

Using artificial wombs to improve preterm infant health outcomes

Researchers at a hospital in the US have successfully used artificial wombs to care for preterm lambs and are now looking at the possibility of human trials. This nine-minute video includes interviews with the researchers and explains the reasoning...

Scientists first observed a sperm and an egg uniting in 1876

Throughout human history, scholars and researchers have speculated on the origin of human reproduction. It wasn't until the late-19th century that the physical process of egg fertilization via sperm cells was observed (in sea urchins), forming the basis for modern fertility research.

Morphine, heroin, codeine, and more were derived from opium

Opium reached the US at about the time early colonists were itching for ways to soothe aches and pains. The active ingredient in the substance was isolated in the early 19th century, eventually leading to the manufacture and commercial sale of morphine, heroin, and other opium-based drugs.

Explore how the placenta acts as lungs, kidneys, and more in the womb

This temporary organ, formed from maternal and embryonic tissue, ultimately attaches to a fetus via the umbilical cord. It transports nutrients, oxygen, antibodies, and more from the mother to the developing fetus. It also carries carbon dioxide and waste away from the fetus. The placenta—which forms only during pregnancy—is expelled during childbirth, or it needs to be removed to prevent toxic maternal infections and extreme blood loss.

Aurea is the first US baby born following polygenic analysis

The child, born in May 2020, was selected by her parents to optimize for certain health qualities based on an analysis of her multifactorial genes by a New Jersey-based company called Genomic Prediction. Her embryo was selected for implantation based on polygenic risk scores for heart disease, diabetes, and cancer.

Due date is calculated from the first day of the last menstrual period—not when sex occurred

The standard counting system considers a woman pregnant from the first day of her last menstrual period, which means someone may technically—for the purposes of measurement—have become pregnant even before she had sex. This standard starting point is used because it reliably marks when the body began preparing for pregnancy—even though it's typically two weeks before conception. On average, most women are pregnant for 280 days from the last menstrual period.

The economics of horseshoe crab blood

Horseshoe crabs are older than dinosaurs and have survived five mass extinctions that wiped most life from the planet. But it's only now that their future as a species is in danger. This blood, worth about $60,000 per gallon, is hyper-sensitized to certain bacteria that are fatal to humans. This 17-minute podcast dives into humanity's pursuit of horseshoe crab blood, a "somewhat magical" mixture heavily relied on by the pharmaceutical industry.

The hormonal disorder PCOS was renamed PMOS in 2026, a move designed to improve care and research by shifting the focus to the hormonal causes of this condition that affects 1 in 8 women.

Horses have four licensed West Nile vaccines—but humans have none

A major hurdle for West Nile vaccine development is the lack of a market for it since so many people are symptomatic for the infections. Still, a growing number of infections, including a 40% spike in 2025, may change that calculation.

Humans aren't the only mammals who go through menopause, but it's rare in the animal world

While scientists are unsure how many mammals actually experience menopause, they do know for sure that humans aren't the only ones. Orcas and some toothed whales (like belugas and narwhals) go through menopause. And a recent study found chimpanzees also experience the condition, though it's late in life.

Nasal congestion is a common side effect of pregnancy, called pregnancy rhinitis

In one recent study, almost 100% of pregnant women experienced this condition in their third trimester. The congestion is likely due to hormonal changes and neurophysiological factors, and it may also worsen at night due to circadian factors and gravitational redistribution when lying down. Treatments include saline nasal irrigation and the use of nasal strips to widen the nasal valve area.

Why pregnant teachers were banned from classrooms

Until the 1970s, many schools required pregnant teachers to leave the classroom by mid-term. In 1974, the Supreme Court ruled these policies unconstitutional, establishing that women could choose to keep working while pregnant.

Geothermal power can reduce the dangerous mining of rare earth elements

Geothermal brines—mineral-rich underground fluids extracted for use in geothermal plants—contain small concentrations of REEs that can be recovered after energy generation. Although researchers suggest that this retrieval requires complex extraction methods at a significant scale to account for high flow rates, the chemical processes also occur in traditional REE processing.

How US horse breeders sourced animals from the Syrian desert

Alexander Keene Richards was a pioneer in thoroughbred racing in the US in the 1800s, a time when every town with a few thousand people had a horse track. This interview highlights how Richards went to great lengths to perfect horse breeding.

Read a deep dive on the 'all-purpose healing' peptide BPC-157.

Hikma v. Amarin is a case the Supreme Court is hearing in 2026 that could impact how much you ultimately pay for prescription drugs

The case explores the liability of a generic drug maker for patent infringement. Hikma Pharmaceuticals launched a generic for Amarin Pharma's Vascepa (a fish oil drug), carving out a still-patented use and instead explicitly selling its product for another unprotected use. But Hikma was sued for its marketing materials that still alluded to the patented indication without outright referencing it.

Experimental hantavirus vaccines and therapies, still under development, have long been funded by the US military.

Horse diving was a popular attraction for 50 years

The event, which took place in Atlantic City, is exactly as it sounds: horses, directed by (sometimes scantily clad) riders, would jump from diving boards into pools. Although it was a popular spectacle for decades, it fell out of favor by the late 1970s.

Watch how plastic products are molded from pellets that began as crude oil

Polyethylene and other plastics are formed by combining ethylene and propylene, which are produced through refining crude oil. These plastics are broken down into pellets called nurdles, or mermaid tears, which are melted and molded to manufacture countless products.

Clever Hans was a 1900s horse that was believed to be able to solve math equations, tell time, and read and comprehend German, until a psychology student discovered how he got his answers.

The first line of 'immortal' human cells, which can divide indefinitely and are used in scientific research, was nonconsensually taken from a Black woman.

See how Budweiser's famous Clydesdales spend their days at Warm Springs Ranch, where roughly 70 to 80 of the beer brand's giant horses can be found at any given time.

At the beginning of the 20th century, a group of young men ate standard American food—replete with food additives like borax and formaldehyde—as part of government research to better understand food safety.

The syncytiotrophoblast is the outer layer of the placenta and the largest human cell, spanning an area about twice that of a king-sized bedsheet.

When a Paris department store hesitated to sell Estée Lauder's perfume, she 'accidentally' broke a bottle, causing the smell to spread throughout the store and shoppers to start asking to buy the scent.

Long before Major League Baseball began allowing instant replay for balls and strikes, an umpire reluctantly used the technology to determine whether a hit was a home run, a move that inadvertently ushered in a new era for the sport.

Larger animals like giraffes, elephants, and blue whales have developed a unique defense against cancer, a phenomenon known as Peto's Paradox

While atoms are normally made of protons, neutrons, and electrons, exotic ones have been built with antimatter—alternate versions of normal matter that live for fractions of a second and are about a billion times as rare.

Poison ivy's rash-causing compound is found in the plant's roots, stem, and leaves—so coming into contact with any part of the plant can lead to rashes for the 85% of people who are allergic to it.

When caught in the mouths of cardinal fish, seed shrimp release glowing, bioluminescent chemicals, which alert predators of the cardinal fish, prompting the shrimp's ejection.

Explore the archaeological treasures of Pompeii, the city buried under volcanic ash when Mount Vesuvius erupted in 79 CE.

Artificial coral reefs have been 3D printed from nontoxic, biodegradable terracotta clay, which coral polyps have used as a foundation for rebuilding marine ecosystems.

Brandi Chastain, the star of the 1999 US victory over China in the 1999 Women's World Cup, was a last-second choice to take the penalty kick that sealed the victory.

Learn how to read a prospectus, the juicy document that any company must file with the SEC before going public.

Some coin denominations have ridges etched on their sides, partly to prevent counterfeiting, in a practice called 'reeding.'

The 19th-century painters of the Hudson River School were among the first American romantics, with portraits that displayed the natural beauty of the young country.

The Ramones' 'Pet Sematary,' the theme song for the Stephen King novel of the same name, was written while the band was admiring the writer's collection of horror memorabilia.

The boiling temperature of water decreases with increasing elevation because the molecules need less energy to overcome the lower atmospheric pressure associated with thinner air.

Elk Cloner, the first computer virus to spread in public, was written as a practical joke by Richard Skrenta, a Pittsburgh high school student.

For centuries, it was common to sleep in two shifts: a few hours at the beginning of the night, and a longer period beginning around midnight

Take a 3D tour of the Hajj, Islam's annual pilgrimage to Mecca, undertaken by over 1.5 million Muslims.