OptiPin vs Regimen

Privacy: on-device vs cloud-by-design

This is the deepest architectural difference between the two apps, and it's not a bug on either side - it's a choice. Regimen is built around a cloud account. That's what makes Android + iOS + iPad sync work, and it means your dose history survives a lost phone without you thinking about backups. The trade is custody: your protocol lives on their servers, and Regimen's App Store privacy label lists email, name, and device/user identifiers as collected and linked to your identity, with identifiers used for third-party advertising.

OptiPin takes the opposite bet. There is no account to create and no cloud database - your doses, labs, photos, and notes are stored on your iPhone, with an optional iCloud backup that you control. If you're logging a peptide stack or an anabolic run, you may reasonably not want that history sitting in anyone's cloud, tied to your email. For a GLP-1 user tracking semaglutide on prescription, this matters less; for most of the people reading this page, it's the first row of the table for a reason.

Forecasting: calibrated vs population-average curves

Both apps draw pharmacokinetic concentration curves, and Regimen's are good - its half-life visualizer covers 40+ compounds with daily, cumulative, and projected views, built on published half-life data. But that's the ceiling of an uncalibrated model: population-average parameters. Real testosterone levels on the same 150 mg/week protocol routinely differ person-to-person by 2× or more, driven by ester absorption, SHBG, body composition, and injection depth. An uncalibrated curve tells you the shape of your levels; it can't tell you the height.

OptiPin starts from the same ester-specific PK models, then recalibrates the curve against your actual lab results - each blood draw pulls the forecast toward your physiology, so the next prediction lands closer than the last. It also models downstream estradiol and DHT from your testosterone protocol, which is where side-effect management actually happens on a multi-compound run. We've documented exactly how this works - models, assumptions, and limitations - in our forecast methodology write-up. The honest caveat applies to both apps equally: these are visualization and education tools. Neither replaces bloodwork, and neither should drive a dosing decision - that's between you and your prescriber.

Multi-compound and anabolic depth

If you're running testosterone plus an AI, a GH peptide, and a healing blend, the question isn't "can the app log six compounds" - both can. It's what the app does with the combination. OptiPin ships 213 compounds with one-tap blend expansion (GLOW, KLOW, Wolverine stack and more), 115 mapped injection sites - 28 core plus 87 advanced - for rotation across that volume of pins, multi-vial inventory with low-stock and reorder alerts, and titration schedules with automatic stepped dose changes. OptiPin then reads across all of it - dosing × Apple Health × logged symptoms × bloodwork - and produces plain-language summaries of what's moving and what to ask your provider about.

Regimen is no slouch here: its 150+ library spans peptides, TRT, PCT ancillaries, and GLP-1s, its cycle management handles on/off protocols, and its Signals engine overlays dose changes on weight, heart-rate, blood-pressure, and sleep charts with 50+ daily check-in markers. The difference in kind is the analysis layer: Signals shows you correlation charts to interpret yourself; OptiPin writes the interpretation. And on the hormone side specifically, Regimen logs estradiol labs but doesn't model your E2 or DHT response - OptiPin does both.

About the "steeper learning curve"

Regimen's comparison page makes one substantive criticism of OptiPin beyond platform reach: that it is "more feature-dense" and that "some users find the learning curve steeper." That's a fair reading, and it's worth answering directly rather than pretending it isn't true.

The surface area really is bigger. OptiPin ships 213 compounds, 115 mapped injection sites, calibrated testosterone, estradiol and DHT forecasting, multi-vial inventory with reorder alerts, titration schedules, and seven free calculators. You cannot offer that and also have three screens. Every one of those is a feature somebody asked for, and each one adds a place to look.

The design answer is progressive disclosure, not fewer features. Setup is a guided flow that asks for one compound and a dose, and you're logging. Site rotation, blends, titration, and forecasting each have an in-app tutorial that appears the first time you touch that subsystem, not on day one. Daily logging runs through a quick-log path that records a dose in a couple of taps without opening any of the above - the depth sits behind the day-to-day, rather than in front of it.

Where the criticism lands, and where it doesn't. If you run one compound - a single testosterone ester, or semaglutide on its own - Regimen is the simpler app and you should probably use it; the extra machinery in OptiPin is machinery you'll never open. The criticism stops landing at the point where your protocol has three or four moving parts. Testosterone plus an AI plus a GH peptide plus a GLP-1 is not a simple thing, and an app that stays simple in the face of it is an app that has stopped modeling it. At that point the density isn't the cost of using OptiPin - it's the reason.

What Regimen's own comparison page concedes

Regimen publishes a "Regimen vs OptiPin" page of its own, last verified on their side 8 July 2026. We link to it because it's genuinely worth reading, and because a competitor's account of your product is the most useful kind of third-party check there is. Three things in it are worth quoting.

On privacy, they give it to us outright. Asked which app is more private, their answer is "OptiPin, by design: no account, data stored locally," and elsewhere that if you want your health data to never leave your phone, "that's a real advantage." Both sides of this comparison now agree on the privacy row, which is worth more than either of us asserting it alone.

On capability, they confirm the forecasting claim. Under a heading titled "Where OptiPin is strong," Regimen describes the app as "genuinely capable," and names bloodwork-calibrated T, DHT, and E2 level modeling, a 100+ site rotation map, and dose calculators as things that "are all there." That is our single biggest differentiator, verified by the competitor with the most incentive to dispute it. (Their 100+ figure is right, and more accurate than the "40+" we used to publish - the shipping build maps 115 sites.)

On platform reach, their criticism is simply correct. Their page returns repeatedly to the point that OptiPin is iOS-only while Regimen runs on iPhone, Android, and the web. There is no rebuttal to make. If you're on Android, stop reading and get Regimen.

What their page doesn't cover, and what we'd point a reader to: the forecast is not just labeled "calibrated," it's documented - the models, assumptions, and failure modes are written up in our forecast methodology. Regimen's Signals engine surfaces correlation charts for you to interpret; OptiPin writes the interpretation. Which of those you want is a real preference, and not one either comparison page can settle for you.

Pricing: identical sticker, different free tiers

The paid tier is identical and easy to verify: both apps cost $4.99/month or $39.99/year. So the subscription price won't decide this for you. The free tiers are where they differ, and Regimen's is the more generous of the two: it's free for one protocol with every feature unlocked and no credit card, indefinitely. OptiPin is free forever for one medication, plus a 14-day full-feature trial that likewise needs no card - and, because there's no account at all, no email either. If you run a single compound and never intend to add a second, Regimen's free tier will carry you further than ours. We'd rather say that plainly than lose your trust over a pricing table.

Since both free tiers are real and neither takes a card, the cheapest honest advice hasn't changed: install both, run your actual protocol in each for a week, and keep the one that fits.

What Regimen does better

Credit where due - these are real advantages, verified on their site on 30 July 2026:

Android, web, and true cross-device sync. Regimen runs on iOS, Android (Google Play), iPad, Apple Silicon Macs, and in a browser, with cloud sync across all of them. OptiPin is iPhone-only. If you're on Android, split your life across devices, or want to check your protocol from a desktop at work, Regimen isn't just the better fit - it's the only one of the two that works.

Two-way health-platform sync on both mobile platforms. Regimen integrates with Apple Health on iOS and Google Health Connect on Android for weight, sleep, and heart data. OptiPin reads Apple Health only, because it only exists on iOS.

A more generous free tier. One protocol, every feature unlocked, no card, no time limit. OptiPin's free tier caps at one medication and its all-features window is 14 days. For single-compound users this is a genuine advantage and we're not going to talk around it.

A bigger free web catalog. Regimen publishes an extensive set of free browser tools - reconstitution calculator with reverse mode, GLP-1 dose calculator, titration planner - plus a large blog, localized into several languages. OptiPin's free peptide calculator, half-life visualizer, and free testosterone calculator are catching up, but Regimen's catalog is broader today.

More in-app languages. Regimen advertises 18+ in-app languages; OptiPin currently ships four (English, German, Spanish, Portuguese). If neither list covers your language, Regimen's odds are better.

Niche extras. CSV import from other tracking apps, side-by-side progress-photo comparison, and a GLP-1 clinical-trial comparison that plots your weight trajectory against published trial averages for semaglutide, tirzepatide, and retatrutide - a genuinely clever feature if weight loss is your primary goal.

Frequently asked questions

Is OptiPin or Regimen more private?

OptiPin, by design: no account, data on your iPhone, optional user-controlled iCloud backup. Regimen is account-based with cloud sync - your data lives on its servers, and its App Store privacy label lists email, name, and device/user identifiers collected and linked to identity, with identifiers used for third-party advertising. Cloud sync is genuinely useful; the trade-off is custody of your dosing history.

Does Regimen run on Android?

Yes - iOS, Android, and the web (plus iPad and Apple Silicon Macs), with cloud sync across devices, Apple Health on iOS and Google Health Connect on Android. OptiPin is iOS-only. If you're on Android, or you want to check your protocol from a browser, Regimen is the better choice; OptiPin simply doesn't run there.

Which app forecasts blood levels more accurately?

Both model PK concentration curves. The difference is calibration: Regimen plots estimated curves for 40+ compounds from population-average half-life data, while OptiPin recalibrates its ester-specific models against your own lab results and additionally models downstream estradiol and DHT. Neither replaces bloodwork - both are visualization tools, not clinical instruments. Full details in our forecast methodology.

Do OptiPin and Regimen cost the same?

The paid tier is identical: $4.99/month or $39.99/year. The free tiers differ. Regimen is free for one protocol with every feature unlocked and no card. OptiPin is free forever for one medication, plus a 14-day full-feature trial that also needs no card and no account. If you only ever run one compound, Regimen's free tier is the more generous of the two.

Is OptiPin harder to learn than Regimen?

OptiPin has more surface area, and Regimen's comparison page is fair to say so. It ships 213 compounds, 115 mapped injection sites, calibrated T/E2/DHT forecasting, and multi-vial inventory - that can't fit in three screens. The design answer is progressive disclosure: guided setup, per-subsystem tutorials that appear when you first touch a feature, and a quick-log path that records a dose in a couple of taps. Running one compound? Regimen is simpler and you should use it. Running four? The depth is the point.

What does Regimen's own comparison page say about OptiPin?

Regimen's "Regimen vs OptiPin" page (verified their side 8 July 2026) concedes that OptiPin is more private "by design: no account, data stored locally," and that data never leaving your phone is "a real advantage." It calls OptiPin "genuinely capable," naming bloodwork-calibrated T, DHT and E2 modeling, a 100+ site rotation map, and dose calculators. Its criticisms - iOS-only, and more feature-dense with a steeper learning curve - are a fair reading, and we answer both above.

Is there a Regimen vs OptiPin comparison from Regimen?

Yes - Regimen publishes its own "Regimen vs OptiPin" page on helloregimen.com, and we link straight to it. We'd encourage you to read both. This page links to Regimen's website and both store listings (theirs, ours) so every claim can be verified at the source - and we say plainly where Regimen wins. You can also check what real users say in our App Store reviews.

Sources & further reading

• Regimen - "Regimen vs OptiPin" (their comparison of us; their stated last-verified date: 8 July 2026) - source for every Regimen quote and concession on this page
• helloregimen.com - platform support, Signals engine, language count, free-tier terms
• Regimen - Peptide Tracker, App Store listing - privacy label (data collected and linked to identity)
• Regimen on Google Play - Android availability
• OptiPin - TRT & Peptide Tracker, App Store listing - OptiPin pricing, privacy label, ratings
• OptiPin forecast methodology - the PK models behind the calibrated T/E2/DHT curves, with stated assumptions and limitations
• Behre HM, Nieschlag E. Comparative pharmacokinetics of testosterone esters - published basis for the ester-specific half-life differences both apps model

OptiPin-side figures (213 compounds, 115 injection sites, 14-day trial) are counted from the shipping build rather than rounded for marketing. Regimen-side figures are their own published claims, quoted and linked rather than paraphrased, so you can check whether they've changed since 30 July 2026. Quotations from Regimen's page are reproduced briefly for comparison and commentary; the page is theirs and linked in full above. If we've got something about Regimen wrong, tell us and we'll correct it.