PepCue vs Protocol.
Protocol, the app at protocolapp.health, is the closest match to PepCue on privacy of anything in this category. Both keep your data on the phone, neither needs an account, and both say so plainly. Where they part ways is what an app should do with your goal. Protocol offers a set of AI tools, one of which builds a full protocol from a goal you describe, alongside pharmacokinetic curves, a 3D injection site map and bloodwork tracking. PepCue publishes graded evidence on each compound and has decided never to suggest what anyone should take.
Last checked September 2026. Competitor features and pricing change, so verify on their own site or App Store listing before you decide.
You want the evidence behind a compound graded on a model you can read, free tracking with no subscription gate, and an app that records your decisions rather than proposing them.
You want AI tools inside the tracker, pharmacokinetic curves, a 3D site map that suggests the next site, bloodwork tracking, and supplements and habits in the same protocol as your peptides, all without an account or a cloud. Protocol has those. PepCue has an in-app assistant that reads your log, but no bloodwork tracking, no supplement layer and no AI protocol builder.
Checked against Protocol's website and its App Store listing in October 2026. More than one app uses Protocol in its name; this page is about the one at protocolapp.health. We have not printed prices, ratings or review counts, and we have not tested its AI tools, so we make no claim about the quality of their answers.
Side by side, verifiable rows only.
| PepCue | Protocol | |
|---|---|---|
| Price | Free to use. You can run a full protocol without paying, and there is no subscription gate on logging, schedules, the calculators or the evidence library. | Freemium. A free tier covers dose logging with a limit on active protocols; a Pro subscription unlocks the AI tools and unlimited protocols. Amounts are left off on purpose. |
| Account required | Not required. Tracking starts without an account, and the browser calculators need no sign-up either. | No. Its site says no sign-up, login or email is required. |
| Where your data lives | Protocols, doses, inventory, weights and check-ins are stored on your device rather than on our servers. | On the device. Its site says data is stored locally and nothing leaves the phone, and its App Store privacy label reads Data Not Collected. |
| AI assistant | PepCue AI, an in-app assistant, answers questions about what you have logged. A safety filter turns away dosing, sourcing, diagnosis and medical-advice questions before they reach the model. | Yes, several AI tools in Pro, including a research assistant, a check-in coach, stack scoring, an interaction checker and a protocol generator. |
| Builds a protocol for you | Never. PepCue explains compounds and does the arithmetic on numbers you enter. It does not tell anyone what to take. | Yes. An AI tool builds a protocol from a goal you describe. |
| Estimated levels | Estimated levels charted from the doses you logged, alongside weight trends. | Pharmacokinetic curves showing estimated concentration, peaks and overlap. |
| Injection sites | A body map records each injection site, shades recent ones and scores how evenly they are spread. It does not advise where to inject. | A 3D body map that tracks rotation history and suggests the next site. |
| Bloodwork | No lab-result or biomarker tracking is advertised, and PepCue does not interpret results. | Bloodwork tracking across a large set of biomarkers. |
| Supplements and habits | PepCue is built for peptides, GLP-1 medications and TRT rather than a general supplement and habit routine. | Peptides, supplements and daily habits tracked together in one protocol. |
| Health app sync | Apple Health on iPhone: with your permission PepCue reads weight, body composition, heart rate, sleep and active energy, and can save logged weight back. Google Health Connect sync is not advertised. | Writes weight and measurements to Apple Health and reads sleep and heart rate. |
| Evidence grading | Every compound carries an S to F evidence tier scored on six axes: human evidence, preclinical depth, mechanism confidence, safety clarity, regulatory clarity and practical relevance. | Not verified |
| Citations | 306 cited sources across 69 compound profiles, plus a generated research index of 274 unique PubMed records, every one pulled from NCBI and re-resolved against live PubMed by an audit script kept in the repo. | Not verified |
| Calculators | 9, free in the browser with no account and no install: reconstitution, blends, GLP-1 titration, pen clicks, vial longevity, unit conversions and BAC water. | A reconstitution calculator in the app, also offered as a free web tool. |
| Affiliate codes or vendor rankings | None. PepCue sells no peptides, ranks no vendors, takes no kickbacks and places no affiliate codes. | Not verified |
What PepCue does differently.
Because the two apps agree on privacy, this comparison is unusually clean. Protocol and PepCue both store your log on the phone, neither asks for an account, and both let you take your data with you. With that settled, the real difference is philosophical: what should a tracker do when you tell it what you want?
Protocol's answer, in its Pro tier, is to help. Its site describes an AI stack builder that takes a goal such as fat loss, recovery or longevity and builds a complete protocol, a research assistant for questions about interactions and half-lives, and stack scoring. PepCue's answer is to decline. It never suggests a compound, an amount or a combination, in the app or on the site, and its calculators only do arithmetic on numbers you entered after deciding them with a licensed provider. Neither position is hidden. They are different products for people who want different things.
What PepCue offers instead is a grade on the published evidence. Every compound carries an S to F tier computed from six scored axes: human evidence, preclinical depth, mechanism confidence, safety clarity, regulatory clarity and practical relevance. The model, the thresholds and a worked example are published. On stacks, PepCue's pages usually reach the same conclusion: the components have been studied alone, and the combination has almost never been tested against placebo.
Behind the grades sit 306 cited sources across 69 profiles, and a generated research index of 274 unique PubMed records pulled from NCBI and re-resolved against live PubMed by an audit script in the repo. Every answer on PepCue is a page someone wrote and sourced, so you can see where it came from. Tracking has no subscription gate, and the 9 calculators run in a browser with no install.
Where Protocol is stronger.
Protocol matches PepCue on the thing many people care about most, privacy, and then does more on top of it. That combination is rare. If you want on-device storage and no account, and you also want AI tools, Protocol offers both, which most AI-heavy trackers in this category do not.
Its pharmacokinetic curves, 3D site map and bloodwork tracking are substantial features. The site map learns your rotation history and proposes the next site, the curves show when compounds peak, overlap and clear, and the bloodwork tracker keeps markers alongside the log. PepCue charts estimated levels and has a body map, but it has no bloodwork tracking.
Protocol also treats supplements and daily habits as part of the same protocol. If your routine is peptides plus a supplement stack plus sleep and training habits, one app for the whole thing is more useful than a tracker built around peptides, GLP-1s and TRT.
Finally, Apple Health runs both ways: Protocol writes weight and measurements and reads sleep and heart rate. PepCue does much the same on iPhone, reading weight, sleep and heart rate and saving weight back.
FAQ.
Do Protocol and PepCue both work without an account?
Yes. Protocol's site says no sign-up, login or email is required and that data is stored locally, and its App Store privacy label reads Data Not Collected. PepCue also starts tracking without an account and keeps protocols, doses and inventory on your device.
Will PepCue build a protocol for me like Protocol's AI does?
No, and that is deliberate. PepCue never suggests compounds, amounts or combinations. It records what you and a licensed provider decided, does arithmetic on numbers you enter, and shows what the published evidence says about each compound.
Is Protocol free?
Protocol has a free tier and a Pro subscription, and according to its site the AI tools and unlimited protocols sit in Pro. We do not print its prices. PepCue is free to use, with no subscription gate on logging, schedules or the calculators.
Which one has better compound information?
They approach it differently. Protocol answers questions through AI tools. PepCue publishes written profiles with an S to F grade from a disclosed six-axis model and citations audited against PubMed. We have not tested Protocol's AI answers, so we make no claim about their accuracy.
Last checked September 2026. Competitor features and pricing change, so verify on their own site or App Store listing before you decide.