Peptides are investigational compounds. The majority have not been approved by the FDA or any regulatory body for human use outside of controlled clinical trials. We cannot and do not recommend that anyone self-administer, purchase, or use these substances.
Providing a calculator is not an endorsement. It is the same reason a chemistry textbook includes measurement tables - knowledge is not permission. Every individual is solely responsible for their own decisions, and those decisions should be made with a licensed physician.
For educational & research reference only - not medical advice
Why labs need this tool
Research laboratories working with lyophilized peptides face a precise reconstitution problem every time they open a new vial. Getting the BAC water volume wrong by even a small margin shifts every downstream concentration and dose - corrupting entire experimental runs and wasting expensive compounds.
Labs use calculators like this to:
Confirm the correct solvent volume per vial weight (mg)
Calculate concentration in mcg/unit or mg/mL for precise pipetting
Standardize dosing across multiple vials or batches
Cross-check manual math before running in-vivo or in-vitro protocols
Precision reconstitution is the foundation of reproducible research
How to read your pen
ANeedle end. Screw on a new pen needle each time. Nothing here tells you the dose.
BCartridge window. Shows the liquid left in the pen. Any numbers printed on the cartridge are a rough "how much is left" guide, not your dose. Don't measure a dose with them.
CDose window: this is the number you read. It shows the pen setting you dialed, in pen units. Read the number that sits on the pointer (pink arrow). It is not mg, and it is not syringe units.
DDose knob. Turn it to dial up or down; each click is one step on your pen. The knob sticks out further as you dial up. Pressing it in delivers the setting, and the window goes back to 0.
Turning the number into a real amount: type the dose-window number into the PEN calculator (or drag its Pen Dial). PenSync turns it into mL, mg of each peptide, and syringe units, using your pen's calibration.
Check before you trust it: priming, maximum dose per dial, and how many clicks make one unit vary by pen. Follow your pen's own instructions.
What this app does & how to use it
Glow/Klow Calc is a free math tool for peptide research. It turns "how much powder, how much water, how much do I want" into the exact line on a syringe or the number on a peptide pen. It runs in your browser, can be installed like an app, and saves your settings on this device only.
What it gives you:
GLOW and KLOW tabs: the standard blend recipes are already filled in. Enter the water you added and see exactly where to pull the syringe, plus how much of every compound that draw contains.
ALL PEPTIDES tab: the same thing for any other peptide (Retatrutide, Tirzepatide, BPC-157 and more). Type its name and mg.
PEN tab (new): for peptide pens. Pick your pen (V2, V3, V4, V5), enter the peptide, mg and BAC water, and how much you want. It tells you how many units to dial on your pen.
Labels: download a full-size label or a Niimbot M2 (1.75 x 0.75 in) label showing the units to pull and what's in each dose.
Guides: compound research notes, blood work to discuss with a doctor (with a letter you can copy), zinc and copper balance, reducing GHK-Cu sting, and an illustrated pen reconstitution video.
Easy reading: "A+ Bigger text" and i buttons that explain unusual words.
How to use it, in 4 steps:
Pick a tab at the top: GLOW, KLOW, ALL PEPTIDES (any other peptide in a vial) or PEN (a peptide pen).
Enter how much water (mL) is in the vial or pen.
Enter what you want: drag the syringe slider, type a target dose and press Set Draw, or on the PEN tab choose what you want to inject.
Read the answer: the marked syringe line, or the big Set pen to / Or pull syringe to boxes. Then download a label if you like.
It's a calculator, not medical advice. Always double-check the math and your product's own instructions.
How this calculator reads
A U-100 insulin syringe marks 100 units to 1 mL - each unit line is 0.01 mL. Since every compound in a GLOW/KLOW vial is dissolved together, they come out of the needle in fixed proportion: change the water volume and every compound's concentration shifts together. Set your reconstitution volume on the left, then either drag the draw line yourself or tell the calculator a target dose for one compound and it'll calculate the exact unit mark - and show what all the other compounds work out to at that same draw.
Compound research notes
BPC-157 Gastric-derived / 15-mer
A synthetic fragment modeled on a protein naturally found in gastric juice. In animal and cell-culture research it's been studied mainly for gut-lining protection and for promoting angiogenesis (new blood vessel growth) at sites of tendon, ligament, and muscle injury - which is why it shows up so often alongside TB-500 in tissue-repair research stacks.
Modeled on a fragment of thymosin beta-4, a protein your body already produces during wound healing. Research interest centers on its role regulating actin (a structural protein in cells), which is linked to cell migration - how new cells travel to and organize at an injury site during tissue repair studies.
A copper-binding tripeptide found naturally in human plasma, saliva, and urine, at levels that decline with age. It's the most clinically studied compound in this blend - widely used in dermatology/cosmetic research for stimulating collagen and elastin production, and studied for antioxidant and anti-inflammatory signaling in skin tissue.
The C-terminal tripeptide fragment of alpha-MSH (a hormone your body produces). Research has focused on anti-inflammatory and antimicrobial signaling, most notably in gut-inflammation models (e.g. colitis), without the pigmentation effects of full-length alpha-MSH.
For any other peptide, search its name on PubMed to read the published studies.
These are summaries of preclinical/research literature, most from animal or in-vitro studies - none of these compounds are FDA-approved therapeutics. This is background reading, not medical advice or a usage recommendation.
Blood work before any research
Not medical advice. This is a general reference list of panels people commonly discuss checking before starting, and periodically during, research peptide use - it is not a prescription or a complete list. Only a licensed clinician can tell you what's appropriate for your history, age, sex, and the specific compound. Get a real baseline before you start, so you actually have something to compare against later.
CMP - electrolytes, glucose, kidney & liver enzymes in one panel
Lipid panel - cholesterol, triglycerides, HDL/LDL
Metabolic / insulin resistance
Fasting glucose + fasting insulin - together give HOMA-IR, a standard insulin-resistance estimate
HbA1c - ~3-month average blood sugar
Thyroid & inflammation
TSH, Free T4, Free T3 - thyroid function
TPO / TgAb antibodies - if autoimmune thyroid issues are suspected
hs-CRP - high-sensitivity marker of systemic inflammation
Liver & kidney
ALT, AST, GGT, bilirubin - liver stress/damage
Creatinine, eGFR, BUN - kidney function
Male-specific
Total & free testosterone, SHBG
LH, FSH - pituitary signaling
Estradiol (sensitive assay)
PSA - if age-appropriate
Female-specific
Estradiol, progesterone - timing relative to cycle matters
LH, FSH
Total/free testosterone, SHBG
Prolactin, and AMH if fertility is a factor
A one-off panel tells you where you stand today; retesting on a schedule (e.g. before, a few weeks in, and after) is what actually lets you or a clinician catch a problem early.
Draft a letter for your doctor
A full, editable letter - rewrite any part of it to fit your real situation, then copy it. The [[PANELS]] line gets swapped for the actual test list (or every category above) when you hit copy.
Zinc & copper balance (GHK-Cu research)
Not medical advice. General reference only - confirm any supplementation plan against real bloodwork and a licensed clinician, not this list.
GHK-Cu delivers bioavailable copper directly into tissue. Zinc and copper share intestinal absorption transporters and are kept in balance partly through metallothionein; sustained copper exposure without a zinc offset can gradually push zinc status down, and the reverse is true of excess zinc suppressing copper. This is why copper-peptide research literature consistently flags zinc status as something to track alongside a GHK-Cu protocol, not something to ignore.
General reference ranges commonly cited in zinc-copper interaction and supplementation literature:
Target dietary ratio: roughly 8:1 to 15:1 zinc to copper is the range most commonly cited to avoid displacing either mineral.
Women: RDA is 8 mg elemental zinc/day (11 mg/day if pregnant; upper intake ~40 mg/day).
During an active GHK-Cu research cycle: many practitioners running longer protocols use 15-30 mg elemental zinc daily, taken several hours apart from copper peptide administration so the two don't compete for absorption in the same window.
Confirm, don't guess: serum zinc, serum copper, and ceruloplasmin can all be checked on a standard blood panel to see where you actually stand before adjusting anything.
Some longer-running protocols build in a short zinc-focused break (1-2 weeks) after several consecutive weeks of copper peptide use. This is common anecdotal practice in the research community, not an established clinical guideline.
Reducing GHK-Cu injection sting
GHK-Cu is one of the more commonly reported peptides for a stinging or burning sensation at the injection site. A few things that are widely reported to reduce it:
Let it warm up. A vial straight out of the fridge stings more going in - pull it out and let it sit at room temperature for 10-15 minutes before drawing.
Make sure it's fully dissolved. Any undissolved powder left in solution is more irritating on injection - gently swirl (don't shake) the vial until it runs clear.
Inject slowly. Pushing the plunger fast increases pressure and irritation in the tissue - a slow, steady push over several seconds is much better tolerated.
Rotate sites. Repeated injections into the same small area compound irritation over time - spread injections across different sites.
Anti-itch cream after, if needed. A thin layer of an over-the-counter hydrocortisone or antihistamine cream on the injection site after injecting is commonly used for residual redness or itching. If a reaction is severe, spreading, or not improving, stop and talk to a clinician.
About & privacy
Glow/Klow Calc is a free, independent calculator for peptide research math. It was made to take the guesswork out of mixing and measuring: you enter what is in your vial or pen, and it shows the numbers, step by step.
How the math works
Concentration = peptide in the vial (mg) ÷ water added (mL).
Volume to draw = the amount you want ÷ concentration.
Syringe units = volume (mL) × 100 on a U-100 insulin syringe (1 unit = 0.01 mL).
Pens are converted through mL using the pen's calibration. If the calibration is unknown, the app will not guess.
Your privacy
Nothing you type is sent anywhere. All the math runs on your phone or computer.
Your settings and My vials are saved on this device only. Clearing your browser data removes them.
No accounts, no ads and no tracking. The page only loads its fonts from Google Fonts.
A shared link carries the setup inside the link itself, so only people you send it to can see it.
Sources: each compound in the research notes links to a PubMed search, so you can read the published studies yourself.
Not medical advice. This is a calculator. It does not recommend doses or tell anyone to use any compound. Always double-check the math and your product's own instructions, and talk to a licensed clinician.
Last updated: October 2026
Video: how to mix a peptide pen
A short illustrated video that walks through reconstituting (mixing) a peptide pen cartridge in 12 steps, from washing your hands to priming the pen. It takes about 1½ minutes and has optional narration.
