Peptide Basics
Peptides come with a vocabulary problem before they come with a pharmacology problem. The first questions people ask are what a peptide actually is, whether buying one is legal, whether a doctor needs to know, and whether any of it shows up on a test. The guides in this section answer those without assuming any background. Each one is sourced the same way as the rest of the site, from labels, regulatory records and published trials rather than from forum consensus.
How Many Peptides Are There? Six Counting Rules, Six Answers
Every count on this page is computed from this site's own registries, with its counting rule stated beside the number: nature's thousands, the library total, approvals, trials, and the compounds with nothing behind them.
Are Collagen Peptides the Same as Injectable Peptides? What the Trials Measured
Collagen peptides are real peptides, but a drinkable food-protein mixture, not a defined sequence. What the skin and joint trials measured, and who paid for them.
What Is a Peptide Half-Life? Why It Differs From How Long It Works
Half-life tells you how fast a drug leaves your blood. Tesamorelin's is 11 minutes and it is dosed daily. Seven questions, seven different answers.
Is Everything a Peptide Vendor Sells Actually a Peptide?
35 of 247 compounds in our library are not peptides. NAD+, 5-Amino-1MQ and SLU-PP-332 alone carry 387 listings, and the distinction changes five things.
Is GLP-3 Retatrutide? What the Peptide Vendor Codes Mean
GLP-3, GLP-3 RT and GLP3-Reta all mean retatrutide. GLP-2 means tirzepatide, GLP-1 S means semaglutide. A decoder built from the listings of every seller we track.
Do Peptide Capsules, Nasal Sprays or Creams Work?
Peptide capsules, sprays and creams barely reach the blood. What the approved versions needed, and why close to half the capsules sold are not peptides.
Peptides and SARMs Are Not the Same Thing
Sold together, chemically unrelated. SARMs bind the androgen receptor and have a documented pattern of liver injury in young, previously healthy men.
Do Peptides Cause Cancer?
No peptide has been shown to cause cancer and no study has looked. The IGF-1 evidence points three ways, and the position peptide users occupy is unstudied.
Do Peptides Show Up on a Drug Test?
Not on a workplace panel, because there is no reagent for them. Yes in tested sport. And a third answer nobody gives: IGF-1 on a routine blood test shows it.
Can You Drink Alcohol on Peptides?
Three different answers. A real interaction on the GLP-1 drugs, a mechanism problem on the growth hormone compounds, and no studies at all for everything else.
How to Tell Your Doctor You're Taking Peptides
Eight guides on this site say tell your doctor and none says how. What to say, when it lands best, what happens to the information, and what if it goes badly.
Why Most Peptides Have No Human Evidence
Four different situations look identical on a product page. What a trial actually costs, why peptide patents are shallow rather than absent, and what really happened when a pharmaceutical company spent a decade on BPC-157.
Are Peptides Steroids?
Chains of amino acids against four fused carbon rings. What actually separates them, why the legal difference matters more than the chemistry, and why the safer option claim compares a measured risk against an unmeasured one.
How Long Do Peptides Take to Work?
For five compounds there is a real answer from trial data. For most of what is sold there is none, and the week-by-week vendor timelines are inventions.
Are Peptides Safe? What Actually Goes Wrong
One word covers approved medicines and grey-market vials. What lab testing found inside those vials, why dosing and injection errors cause most of the harm, and what is still unknown.
Are Peptides Legal? What "Research Use Only" Actually Means
Four different legal questions share one word. What research use only actually does, why the FDA reads intent from the whole page, and why removal from a list is not permission.
What Are Peptides? A Plain-Language Guide
What a peptide actually is, how the category differs from proteins, hormones, steroids and supplements, what research use only means, and the words you need before reading anything else.