Peptides may have predated ribosomes—the cell's protein factory

Some scientists have hypothesized that peptides and RNA molecules may have coevolved as a single, mixed "chimeric" molecule, fueling the beginning of protein production and predating a primitive version of the ribosome. All life today uses ribosomes to make peptides. (Some users may experience a paywall.)

The US FDA defines peptides as being 40 amino acids or less.

Peptide research dates back to the late 1800s

Peptide science dates back to the late 1800s with some early peptide synthesis work, but peptides took off in the medical sphere after surgeon Frederick Banting and his colleague's isolation of insulin from dog pancreases in 1921.

Diabetes drug GLP-1 is a peptide (that's what the 'P' is for).

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.

Peptides like GLP-1 account for 31 of 370 new drugs approved by the US FDA between 2016 and 2023.

China is producing many peptides or peptide components sold in the US.

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

Peptides like BPC-157 are marketed based largely on animal studies, not human research

BPC-157, which purportedly helps with tissue repair and muscle growth, can cause concerning side effects, including pain and swelling. TB-500, another experimental peptide, is marketed for wound healing, but it hasn't undergone any clinical human trials, and high levels of this peptide have been linked to tumor growth. (Some users may encounter a paywall.)

The World Anti-Doping Agency has banned many peptides

The global body has an entire section dedicated to banned peptide hormones, including ones that may stimulate growth hormones and testosterone. BPC-157 was added to the list in 2022.

Hormone and peptide compounds imported from China soared in 2025

US customs data indicates that these imports doubled to $328M in the first three quarters of 2025, from $164M in the same period of 2024. The imports include GLPs, among other products. (Some users may experience a paywall.)

Two festival-goers were hospitalized after receiving trendy peptide injections, raising safety questions that may extend beyond the event.

Peptide TB-500, promoted for regenerative healing, is not FDA approved

Watch a board-certified sports medicine therapist detail his thinking about this synthetic peptide; he says it's "promising but unproven." He notes that this product is designed to mimic the natural protein thymosin beta-4, found in human and animal tissues, which promotes wound healing. TB-500 is classified as a research peptide for recovery, meaning it's not approved for human use and has not yet undergone rigorous human trials on its safety and efficacy.

See the first dog ever treated with insulin—a peptide

Frederick Banting and his graduate student Charles Best were the first to isolate the peptide insulin from dogs. They induced diabetes in the animals and then treated them with this peptide.

Poliomyelitis is derived from Greek

Polio, formally called poliomyelitis, comes from the Greek words for gray (polios) and marrow (myelos)—a reference to the spinal cord tissue that, when infected by the virus, causes paralysis.

BPC-157 stands for Body Protection Compound-157.

The US FDA issued a 2025 warning about BPC-157 and other popular peptides that are marketed for various regenerative properties.

The Greeks named their dogs with short names similar to modern ones.

Umami synergy—combining glutamates and nucleotides—can amplify a meal

While glutamates are known for triggering the umami taste through specific taste receptors, nucleotides like IMP and GMP can bind alongside glutamates to enhance the receptor's response. This union explains why certain classic food combinations like bacon and eggs taste exceptionally savory.

The word 'Peloton' comes from the word for the main group of riders in a cycling race

The word itself is French for "ball," but became the inspiration for the word "platoon" in the 17th century to describe a group of soldiers. Now, it's a common cycling term and the main focal point in cycling races.

GLP-1 drugs, first used to manage diabetes, were derived from Gila monster saliva.

Collagen supplements typically come from animal sources like fish, pigs, or cattle

Eating collagen-rich foods won't lead to more collagen in the body because your digestive system breaks down consumed collagen into amino acids. Instead, eating a healthy diet of proteins and greens helps your body to produce collagen. Collagen supplements derived from animal skin and bones are typically sold in a prebroken-down peptide formulation called hydrolyzed collagen so they can be absorbed through the gut into the bloodstream.

Animals' stomach lining produces cheese

Cheesemaking would be impossible without rennet, the enzyme that separates milk’s liquid and solid components. Rennet occurs naturally in the stomach lining of young goats, cows, and lambs to help them digest milk, a process that also allows cheesemakers to use it to make curds. Now we have plant-based rennet that comes from thistles, artichokes, and other similar plants.

'Melancholia' was the ancient Greek term for depression

"Melancholia" in Hippocrates's time was derived from the Greek word for black bile. This term made sense in its context since the Greeks believed that depression stemmed from an improper balance of the four humors.

How muscles get their names

There are more than 600 muscles that crisscross the human body, and each has a name that's more than a simple label. Muscle names also typically communicate the muscle's size, behavior, length, location, appearance, direction, and attachments to bone. These names usually have Greek or Latin roots, such as in the case of the deltoid muscles, which are named in reference to the Greek letter delta (𐤃).

What we can learn from how penguins express affection

Pebbling, a term used to describe small acts of love within a relationship, comes from penguins. Male gentoo penguins, a species of penguin that lives on sub-Antarctic islands, present pebbles to their potential mates later used to build nests. This small but helpful act is something we humans can learn from. Think of the “pebbles” you can share with loved ones on a daily basis.

Monosodium glutamate is a sodium salt form of a naturally occurring amino acid

Monosodium glutamate myths originate from a 1968 letter to the New England Journal of Medicine, in which unpleasant symptoms after eating Chinese food were dubbed Chinese restaurant syndrome without medical data. Subsequent studies show this savory flavor enhancer—found in tomatoes, mushrooms, and other foods—is safe in moderation.

Snake venoms are repurposed proteins responsible for other bodily functions

Just as saliva aids digestion in humans, proteins responsible for bioactivities such as digestion and blood clotting were eventually secreted in the glands and fangs of snakes across evolutionary history. Organisms that could not withstand the effects of these molecules (e.g., excessive bloodstream clotting) became ideal prey for snakes.

How science came to understand umami

Before Dr. Kikunae Ikeda sat down in 1907 and pondered the taste of dashi, scientists typically agreed upon four types of taste: sweet, salty, bitter, and sour. He boiled 90 pounds of kelp into a resin that he then stripped of different compounds until he was left with a single ounce of brown crystals. Testing later revealed these crystals were glutamate, an amino acid and one of the protein's building blocks.

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.

Psychedelic compounds: a visual library

However psychedelic experiences manifest, they all begin with the presence of psychoactive compounds. Learn about their various chemical compositions in this structural library of psychedelic compounds. Clicking on an entry will take readers to a new page where they can learn about the chemistry and pharmacology of each compound, as well as the drug's possible applications.

Ancient Romans helped develop modern cheese production techniques

The ancient Romans loved cheese and experimented with different processes to elevate its flavor, like aging. Some of their innovations, like Pecorino Romano, you can still find today. Others, like the smoked goat-milk Caseus, we only know about through historical records.

The longest word in English is 189,819 letters long

The wildly-winding word (so long that we can't fit it here) is the proper name for titin, a protein that keeps muscles elastic.

GLP-1 drugs are under investigation for treating Alzheimer's, Parkinson's, and drug addiction

Researchers are investigating GLP-1 applications for a variety of chronic conditions. One area of interest stems from how study participants using GLP-1 for diabetes and obesity reported describing less longing for wine and cigarettes while taking the medication—intriguing researchers about using the drugs for addiction applications. The drug, they theorize, could bind to receptors that mediate desire. (Some users may experience a paywall.)

Watch how proteins are created from DNA

When a DNA sequence—a gene—is activated, a copy of the activated portion is created in the form of RNA, a single-stranded version of DNA, in a process known as transcription. This RNA, called messenger RNA, leaves the nucleus and travels to a ribosome, a structure within a cell, which uses it to build a chain of organic compounds that fold into a protein.

Food companies are exploring 'GLP-1 friendly' diet labels

Producers of foods like Healthy Choice frozen meals are placing "GLP-1 friendly" labels on their food, but there's no regulation about what that label means. Nutritionists say that GLP-1s can help reduce appetite, but healthy, balanced diets are a necessary complement to the medications. Data shows that about half of GLP-1 users quit these medications within a year and then rapidly regain weight, underscoring the importance of also prioritizing healthy eating.

Cells translate genetic information into proteins using RNA messengers

Genes are segments of DNA, each composed of a sequence of nitrogenous bases. Within the nucleus, these sequences are copied into a single strand of ribonucleic acid during transcription. This strand leaves the nucleus and is translated by ribosomes into a chain of amino acids that folds into a functional protein.