Basics
10 GUIDESDo 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.
Calculating and injecting
10 GUIDESWhat Bloodwork to Run Before and After
A number without a baseline is not information. Which tests are worth running, and why the glucose test most people would order is the one that misses it.
What Is the Best Time of Day to Take Peptides?
For growth hormone compounds the timing advice has real physiology behind it. For most peptides no study has compared one hour with another, in either direction.
Can You Mix Two Peptides in One Syringe?
Nobody has tested it for peptides. In the one class where mixing was studied, one pairing is allowed, in one order, and three must never be mixed at all.
mcg vs mg: The Peptide Dosing Mistake to Avoid
1 mg equals 1,000 mcg. Why vials and protocols use different units, the three ways the error actually happens, and the one division that catches it.
How to Read an Insulin Syringe
U-100 insulin syringes are the standard measuring tool for peptides. Learn how to read the units, convert units to milliliters, and draw the exact dose every time.
What Does a Peptide Actually Cost Per Dose?
Sticker price is misleading. How to work out cost per dose, monthly cost, and cost per mg, and how to plan your reorder date.
Where to Inject, and Why Rotation Matters
The four subcutaneous sites, why the shortest needle is recommended for everyone, and how to rotate properly. In one survey 98% of people said they rotated and a third were doing it wrong.
How to Tell Your Dose Calculation Is Wrong
A calculator gives you an answer whether or not your inputs made sense. Four numbers give a wrong dose away before you draw it: under 2 units, over 50 units, fewer than three doses per vial, or a blend where you used the label total.
How Much Water Do I Add to a Peptide?
There is no single right amount. What the water actually changes, a worked example, and how to pick the amount that makes your dose easiest to measure.
How to Reconstitute a Peptide: A Step-by-Step Guide
Mix peptide powder with bacteriostatic water, step by step. What you need, how much water to add, why you swirl instead of shake, and how to store it after.
Storage and handling
7 GUIDESRunning Multiple Peptides: Tracking, Stopping, Costs
With one peptide you have an experiment. With three you have an anecdote. What multiplies, what to write down, and what to stop first when something goes wrong.
Bacteriostatic Water vs Sterile Water
They start as the same water. One has a preservative and one does not, and that single difference decides whether a vial lasts six hours or twenty days.
How to Store Peptides: Before and After Mixing
Two clocks run on a mixed vial: one for germs, one for the molecule. Where the 28-day rule actually comes from, why the same drug gets different numbers in different products, and what a clear solution does not tell you.
My Peptides Arrived Warm. Are They Ruined?
Dryness is what protects a freeze-dried peptide, not coldness. Why a warm delivery is usually fine, why the seal matters more than the temperature, and why the vial that arrived cold carries a risk the warm one does not.
Traveling With Peptides: What the Rules Actually Cover
TSA's rules for liquids, needles and ice packs are generous, and every one of them is written about medication. What that means for a research-labelled vial, plus cars, hotel fridges and borders.
My Peptide Went Cloudy. Is It Ruined?
One question decides almost everything: when did it go cloudy? Immediately is usually a dissolving problem. Later is aggregation or contamination, and that one does not come back.
How Many Times Can You Puncture a Vial?
The stopper was tested to four punctures. Daily dosing goes through it thirty times. What coring is, what the research actually measured, and why the 28-day rule is really a puncture count.
Buying and safety
7 GUIDESMy Peptide Vendor Vanished. What Now?
How you paid decides most of what happens next. The dispute deadlines are shorter than people assume, push payments have no reversal, and the recovery firms that appear afterwards are the second scam.
It Arrived, But It's Wrong. What Now?
A different claim from an order that never came, and a weaker one. Why accepting delivery narrows your rights, and the return rule most people have not heard.
How to Read a Peptide COA (Certificate of Analysis)
What HPLC purity and mass spectrometry each establish, what purity is actually good enough, why the lot number matters more than the percentage, and the red flags that mean a COA is worthless.
Why Does My Peptide Injection Itch or Welt?
Injection-site irritation, a mast cell histamine reaction, or a true allergy. How to tell them apart, which peptides cause welts, and the signs that mean get help now.
What Peptide Therapy Actually Costs
The same peptide costs $40 or $1,200 a month depending on the route you buy it through. What each price includes, why published figures disagree fourfold, and the year-one total.
How to Vet a Peptide Vendor
Independent third-party COAs, HPLC purity, mass spectrometry, US synthesis, and the red flags that mean walk away.
When an Injection Site Reaction Means Stop and Get Seen
A normal reaction gets bigger while hurting less. An infection gets bigger while hurting more. The signs that mean stop guessing, and the ten-second test that sorts most of it.
Understanding compounds
9 GUIDESThe Skincare Peptides, Sorted Out: Matrixyl, Argireline
The one group here with well-designed trials, small effects and near-zero risk. And a penetration problem that decides whether any of it reaches anything.
The Longevity Peptides, Sorted Out: SS-31, Epitalon, MOTS-c
One has an FDA approval narrower than the marketing suggests. One has human data belonging to a different substance. Two are studied almost entirely in mice.
The Nootropic Peptides, Sorted Out
Five compounds, five kinds of thing. What each was actually tested for, why Dihexa's mechanism papers were retracted, and which ones have human trials at all.
The Growth Hormone Peptides, Sorted Out
Ten compounds plus three blends, two mechanisms, one approved drug. How the GHRH analogs differ from the ghrelin mimetics, why half-lives run from eight minutes to eight days, and which three have anything behind them.
BPC-157 and TB-500: What the Healing Pair Actually Is
TB-500 is a seven amino acid piece of a protein, not the protein itself, and the research belongs to the full version. What the studies actually found for each, where they stand legally, and why the pairing is habit rather than science.
Semaglutide vs Tirzepatide vs Retatrutide: What Is Actually Different
One receptor, two, or three. How these three compare on mechanism, published trial weight loss, side effects, legal status, and real cost per dose.
The Immune Peptides, Sorted Out: Thymosin Alpha-1 and More
One has 600,000 treated patients and no FDA approval. Its largest trial was negative. The other three range from early evidence to none at all.
Melanotan II: Side Effects, Risks, and What Is Actually Documented
Melanotan II is approved nowhere and stimulates the cells moles are made of. What the case reports document, what vial testing found, and the emergency signs.
GHK-Cu: Three Different Products Under One Name
A cosmetic serum, a compounded cream and an injectable vial. The topical has human trials behind it, the injectable has none, and in 2026 the FDA split the two apart.
Life stages
5 GUIDESPeptides Under 25: What Nobody Has Studied
Raising growth hormone accelerates bone maturation, so the compound sold to make you bigger may make you shorter. And nobody has studied any of it under 25.
Peptides in Perimenopause: What Has Actually Been Studied
One group has real evidence and menopausal women were underrepresented in it. For everything else, a search for trials in this population returns nothing at all.
Peptides and Men in Midlife
Testosterone improved sexual function and not vitality. Clinically significant improvement reached 3% and 10% of men. The peptides bundled with it have nothing.
Peptides, Fertility and Pregnancy: What the Labels Say
Tirzepatide reduces oral contraceptive absorption and semaglutide does not. Fertility can return on both. Neither is stated alongside the other anywhere else.
Peptides After 65: What the Trials in Older Adults Found
The unusual case where evidence exists. A trial in older adults was stopped early, and a two-year study raised lean mass without improving strength or function.
News
5 ARTICLESRetatrutide FDA Filing Set for Q1 2027. What That Means
Lilly named the filing window in an SEC filing. Filing is not approval, the trials are done, and a prescription is realistically 2028 rather than next year.
Compounded Semaglutide: What Actually Changed, and What Is Still Legal
The shortage route closed in 2025 and a narrower one remains. Two drugs, two dockets, four different deadlines, and a proposed rule that would close the rest.
The FDA Warning Letters, and How Little It Took
Five letters posted at once. The striking part is how mild the cited claims were, and that bacteriostatic water and a dose calculator counted as evidence.
Five More Peptides Go Before the FDA. What Is Actually Known About Them
GHK-Cu, Dihexa, LL-37, PEG-MGF and Melanotan II go before the FDA compounding panel by the end of February 2027. The evidence, the safety record, and why this slate is a harder case than July's.
The July 2026 Peptide Vote: The Record, and What It Is Worth
An FDA advisory panel recommended six peptides for compounding against the written advice of the agency's own scientists. What the vote was, what it was not, and what a favorable vote on this list has historically been worth.
Commonly confused peptides
Compare toolHGH vs Sermorelin
Distributing HGH for anti-aging is a federal felony carrying five years. Sermorelin lost to it commercially in 2008 and can still be legally compounded.
IGF-1 LR3 vs IGF-1 DES
Neither has a single published human trial, and sources give LR3's half-life as anywhere from 6 to 30 hours. There is an FDA approved IGF-1, and it is neither of these.
Thymosin Alpha-1 vs LL-37
One is approved in 35 countries and its largest trial found nothing. The other has never been injected in a published study.
Cagrilintide vs Semaglutide
Both were tested in the same trial, in the same people, over the same 68 weeks. Semaglutide won on weight, and the combination beat both while coming in below their sum.
Retatrutide vs Tirzepatide
Retatrutide's 28.3 percent is being set against tirzepatide's 22.5 percent. Different trials, different lengths, and one of the numbers comes from a press release.
PT-141 vs Kisspeptin
Both are sold for sex. One works on desire and is FDA approved, the other works on hormones and stops working within two weeks.
MOTS-c vs SS-31
One has an FDA approval and a failed Phase 3. The other has never been given to a person in a published study.
Tesamorelin vs CJC-1295
Two GHRH analogs tested for the same condition. One completed two Phase 3 trials and got approved. The other's Phase 2 was halted in 2006 and never restarted.
Melanotan I vs Melanotan II
Not two versions of one compound. One is an FDA approved implant for a rare disease, the other is approved nowhere and warned against by four regulators.
Epitalon vs MOTS-c
Two longevity peptides with no published human trial between them. Epitalon's famous human data belongs to a bovine extract, and MOTS-c is something your body already makes.
Glutathione vs NAD+
Both are sold as injections. NAD+ cannot enter cells intact, and a six month trial found oral glutathione raising body stores the injection is meant to fix.
Semax vs Selank
Same Russian lab, same seven amino acids, built for different problems: Semax for alertness, Selank for anxiety.
GHK-Cu vs Matrixyl
Two topical skin peptides with very different evidence: one carries copper, one carries a fat tail, and the most sold version of Matrixyl is built on the same tripeptide as GHK-Cu.
BPC-157 vs TB-500
Both are sold for tendon and muscle repair. BPC-157's human trials were enemas for ulcerative colitis, and TB-500's trials did not even use TB-500.
CJC-1295 with DAC vs without DAC
One name, two drugs: one has a measured half-life and three published human trials, the other has never been tested in a person.
Ipamorelin vs CJC-1295
They act on different receptors and are usually sold in the same vial. Each has human trials; the combination everyone buys has none.
MK-677 vs Ipamorelin
Same receptor, a pill against an injection. MK-677 has far more human data, and that is exactly why we know more about what is wrong with it.
KLOW vs GLOW
These are not two products. One contains the other: KLOW is GLOW plus KPV, and neither blend has ever been tested as a blend.
Sermorelin vs Ipamorelin
Two growth hormone peptides sold side by side. One was an approved drug and can still be compounded on prescription. The other was voted down in October 2024.