Dog peptide calculator

Bacteriostatic water and dogs

This is the most-repeated claim in the dog-peptide community and one of the least-sourced: dogs cannot have bacteriostatic water, the alcohol is bad for them. It is stated with total confidence, usually with no citation, and it sends people toward single-use sterile saline for a multi-dose vial, which carries its own sterility tradeoff.

Here is the check. Adequan Canine is an FDA-approved injectable for dogs. Its label formulation is 100 mg/ml polysulfated glycosaminoglycan and 0.9% v/v benzyl alcohol as a preservative — the same preservative at the same concentration as bacteriostatic water. Label dosing is 2 mg/lb intramuscularly, twice weekly for up to four weeks.

Run the arithmetic and an Adequan dose delivers about 0.41 mg/kg of benzyl alcohol, deliberately, twice a week, with an FDA approval behind it. Where a peptide draw lands against that is a question about body weight, not about peptides. A 0.1 ml draw of bacteriostatic water carries 0.94 mg of it: under a tenth of an Adequan dose for a 30 kg retriever, and more than half of one for a 4 kg toy breed. Small dogs are where this stops being a rounding error, which is why the calculator above prints your dog’s own number and the ratio instead of a typical case.

What that does not mean: it doesn’t make bacteriostatic water correct for every situation, it says nothing about cats, and it isn’t a reason to override a vet who wants saline for a reason of their own. What it does mean is that “the benzyl alcohol will hurt your dog” is not a blanket fact. It is a claim with a body weight attached, and you can now check yours instead of taking a forum’s word for it.

What the canine evidence is, and isn’t

Taking BPC-157 as the example, since it is what most people arrive here for:

• A 2020 preclinical safety evaluation in Regulatory Toxicology and Pharmacology covered single-dose and repeated-dose toxicity, local tolerance, anaphylaxis, genotoxicity and teratogenicity across rats, dogs, rabbits and guinea pigs, and reported it well tolerated without serious toxicity.
• A 2022 pharmacokinetic study in beagles dosed 6 mcg/kg intravenously and 6, 30 and 150 mcg/kg intramuscularly, measuring 45–51% intramuscular bioavailability and a plasma half-life of a few minutes.
• What does not exist is a controlled canine efficacy trial for any of the reasons people actually reach for it — arthritis, a torn cruciate, post-surgical recovery, gut trouble. Toxicology and pharmacokinetics tell you a compound is tolerated and where it goes. Neither tells you it works.

One thing worth flagging that owners of older dogs raise regularly and rarely get a straight answer on: BPC-157 and TB-500 are both described as promoting angiogenesis. In a dog with a known or suspected mass, that is a specific reason to have the conversation with a vet first rather than after.

Where the dose comes from

Not from us. There is no approved peptide dose for dogs, so a “typical for a dog this size” chip would be us manufacturing a veterinary recommendation and dressing it as a convenience. The micrograms-per-kilogram figure is the one number on this page that is a judgment about an animal rather than a fact about an object, and it stays yours.

In the US, extralabel use of a drug in an animal is permitted under AMDUCA within a valid veterinarian-client-patient relationship, and FDA GFI #256 sets out the agency’s position on compounding animal drugs from bulk substances. A vet is not a box to tick on the way to a number — they are the person who can tell you whether the limp is the thing you think it is.

Questions

Is bacteriostatic water safe for dogs?

The claim that it isn't is repeated constantly and almost never sourced. Here is the reference that makes it checkable: Adequan Canine is an FDA-approved canine injectable, and its label formulation is 0.9% v/v benzyl alcohol — the identical preservative at the identical concentration to bacteriostatic water. It is given at 2 mg/lb intramuscularly, twice weekly, which works out to roughly 0.41 mg/kg of benzyl alcohol per dose. Whether a peptide draw is trivial next to that depends on the dog, and that is the part confident answers on both sides leave out. A 0.1 ml draw carries 0.94 mg of benzyl alcohol: under a tenth of an Adequan dose for a 30 kg retriever, and more than half of one for a 4 kg toy breed. The calculator above prints your dog's actual figure and the ratio, and says so plainly when a draw lands above the Adequan reference rather than below it. None of this makes bacteriostatic water the right choice for every case — a vet may prefer sterile saline for other reasons, and single-use saline is genuinely cleaner if you can use a fresh vial each time — but 'the alcohol will hurt your dog' is not a blanket fact. It is a claim with a body weight attached.

Where does the 'benzyl alcohol is toxic to pets' idea come from?

Two real things, both of which got over-generalized. Cats are genuinely more sensitive: they are deficient in glucuronidation, one of the pathways that clears benzyl alcohol, and the related compound benzyl benzoate has an acute oral LD50 about ten times lower in cats than in dogs. And in human medicine, 'gasping syndrome' was reported in premature neonates given benzyl-alcohol-preserved flushes above 99 mg/kg/day, in infants whose glycine conjugation pathway had not developed yet. Both are true. Neither is a statement about an adult dog receiving a tenth of a milligram.

What is the U-40 syringe problem?

U-100 syringes hold 100 units per ml. U-40 syringes hold 40. The barrels look identical, both are marked 'units', and U-40 is the veterinary standard for Vetsulin and Caninsulin — so it is exactly what a household with a diabetic dog already has in the drawer. Every peptide calculator on the internet, including our human one, silently assumes U-100. Draw a U-100 number on a U-40 barrel and you give 2.5 times the intended dose. This is the only genuinely dangerous mistake available on this page, which is why the syringe standard is a control rather than an assumption and why the cross-reading is shown even when nothing is wrong.

Why won't the calculator suggest a dose per kg?

Because there isn't one to suggest. No peptide is FDA-approved for dogs, so any number we put in that field would be us inventing a veterinary dose for an animal we have never examined. We will do the arithmetic on your vet's figure all day long. We will not be the source of it. Every other field on the page describes an object — a vial, a volume, a barrel — and those are facts we're happy to prefill.

Can I just scale a human dose down by weight?

Straight linear scaling is the common approach and it is known to be imperfect. Metabolic rate scales closer to body weight to the 0.75 power than to body weight itself, which is why veterinary pharmacology often uses that exponent or body surface area instead — a small dog needs proportionally more per kilogram than a linear conversion suggests. There are also species differences that no scaling rule captures: in beagles, BPC-157 showed 45–51% bioavailability after intramuscular injection, which is a species-specific measurement, not something you can derive from a human figure. This calculator deliberately does not apply an allometric correction on your behalf, because doing so would mean silently changing the number your vet gave you.

My dog is tiny and the calculator says the draw is too small to measure. Now what?

Use more liquid in the vial. This is the most common real problem on this page: a 4 kg dog needs a dose that, at a concentration mixed for an adult human, works out to well under one unit — a volume no barrel can show you. The fix is never a steadier hand, it's a thinner mix, and the calculator suggests a volume that lands the draw somewhere you can actually read. If the required volume is more than the vial physically holds, a smaller-milligram vial is the cleaner answer.

What does the canine research actually show?

For BPC-157 specifically, more than most people assume and less than the forums imply. A 2020 preclinical safety evaluation in Regulatory Toxicology and Pharmacology examined single-dose and repeated-dose toxicity, local tolerance, anaphylaxis, genotoxicity and teratogenicity across rats, dogs, rabbits and guinea pigs, and reported it well tolerated without serious toxicity. A 2022 pharmacokinetic study in beagles measured intravenous and intramuscular dosing at 6, 30 and 150 mcg/kg, finding 45–51% intramuscular bioavailability and a very short plasma half-life. What does not exist is a controlled canine efficacy trial for any of the uses people are actually pursuing — joint pain, post-surgical recovery, gut issues. Safety data and pharmacokinetics are not evidence that it works.

Does this work for cats?

Don't use this page for a cat. The arithmetic would be the same but the benzyl alcohol comparison would not, and that is the section most likely to be read as reassurance. Cats clear benzyl alcohol differently from dogs and are meaningfully more sensitive to it. The dose ranges, the syringe conventions and the body weights are all different too. This page is about dogs.

Should I be talking to a vet?

Yes, and not as a formality. In the US, using a drug outside its approved labeling in an animal is legal under AMDUCA but requires a valid veterinarian-client-patient relationship, and FDA's GFI #256 governs what may be compounded from bulk drug substances for animals. Beyond the legal position, the practical one matters more: a vet can tell you whether the thing you're treating is what you think it is. Several of the most common reasons people reach for peptides in older dogs — a limp, stiffness, a mass — have differential diagnoses where a pro-angiogenic compound is a specifically bad idea.