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 health data, email, name, photos and user/device identifiers as collected and linked to your identity.

OptiPin takes the opposite bet. There is no account to create and no OptiPin server holding your data – your doses, labs, photos, and notes are stored on your iPhone. Since August 2026 there is optional iCloud Sync across your own Apple devices, which runs through your iCloud account, not ours. Progress photos never sync. 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 in-app curves cover 150+ 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 200+ 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 writes plain-language AI summaries of what's moving and what to ask your provider about. Since July 2026 a cycle view also puts phases, doses and bloodwork on one timeline.

Regimen is no slouch here: its 200+ library (150+ with PK curves) spans peptides, TRT, PCT ancillaries, and GLP-1s, it plans titration step-ups and on/off cycles, and its Signals engine overlays dose changes on weight, heart-rate, blood-pressure, and sleep charts with 50+ daily check-in markers. The difference is in the analysis layer: Signals surfaces short written observations about single trends (for example, weight dropping faster since a dose change), while OptiPin's AI summaries read across doses, labs, check-ins and Health data together. On the hormone side specifically, Regimen logs estradiol labs but doesn't model your E2 or DHT response – OptiPin does both.

Wearable data. Both apps read sleep and heart data from Apple Health and set it against your doses. OptiPin goes one step further and turns your Apple Watch nights into a nightly recovery score and a daily strain score. Its comparisons (mornings after injection days, weeks on a compound against weeks off, the six weeks after a large dose change) adjust for weekday and the previous day's training before they report anything. Regimen's Signals reports how a metric moved against your own baseline after a dose change.

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 200+ 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. We last re-read it on 29 September 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 and Android (their page says the web too). 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.

Where Regimen's page is out of date

We re-read Regimen's "Regimen vs OptiPin" page on 29 September 2026. Its feature table marks three OptiPin features as "Not advertised" and its FAQ makes two more claims about the app. All five were already wrong on that date. Below is what shipped and when, so you can check each one against OptiPin's public version history on the App Store.

"Supply / vial tracking: Not advertised." OptiPin has tracked inventory since August 2025 (version 0.7.9: remaining medication at a glance, with a reminder before you run out). Per-vial counts followed in version 1.0.7. Mixed vial sizes, refill costs and low-stock alerts came in 2026. "Inventory, discard dates and low-stock alerts" is a named bullet in our App Store description.

"Progress photos (side-by-side): Not advertised." Progress photos shipped in version 1.4.2 on 2 July 2026. Compare, timeline and gallery views followed in version 1.5.0 on 22 July 2026. Both are in the App Store's version history.

"Insights engine (connects labs + how you’re responding to your doses): Not advertised." The first line of our App Store description is "See how your doses, bloodwork and symptoms trend together over time." The Medication Impact view has summarized how each medication lines up against your health markers since October 2025. On top of that, OptiPin's AI insight summaries write up how your doses, labs, check-ins and Apple Health data are moving together. Since July 2026, the cycle view also puts your blood draws on the same timeline as your doses and cycle phases. Regimen's Signals writes short observations about individual trends. OptiPin's AI summaries read across all of your data at once. Since September 2026 (version 1.5.7), OptiPin's Health Trends also reads your Apple Watch nights against your doses: recovery on mornings after injection days, plus HRV and sleeping heart rate in weeks on and off each compound. Neither app is missing an insights layer.

"Regimen pulls from a library of 200+ compounds and brands versus OptiPin's 100+." OptiPin's library is also 200+ compounds, which is the figure on our App Store listing.

"OptiPin offers level projections for testosterone, DHT, and GLP-1 compounds, but doesn't include the same pharmacokinetic half-life visualization that Regimen provides for 150+ compounds." OptiPin has drawn testosterone curves since May 2025 and GLP-1 curves since November 2025. It estimates estradiol as well. Our listing names level estimates for 40+ further compounds. Since 13 July 2026 every compound you log can sit on one chart. Regimen's curve library is larger (150+ compounds by its count), so that part of the comparison is fair. "Doesn't include" is not.

Two points on their page are right. OptiPin is iOS only. OptiPin's subscription also costs less than Regimen's.

Dates come from Apple's public version history for OptiPin and from our release notes. Regimen's wording is quoted from their page as it read on 29 September 2026. If they update it, we will update this section.

Pricing: OptiPin costs less

These used to cost the same. On the US App Store on 29 September 2026, OptiPin Premium is $4.99/month or $39.99/year and Regimen Premium is $7.99/month or $49.99/year. Regimen's own page agrees that OptiPin's subscription costs less. The free tiers are now close to identical: both are free for one compound with no time limit and no card. Both also offer a 14-day trial. OptiPin's needs no email either, because there is no account.

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 29 September 2026:

Android and cross-platform sync. Regimen runs on iOS, Android (Google Play), iPad and Apple Silicon Macs, with cloud sync across all of them. OptiPin is iPhone-only; its iCloud Sync only reaches your other Apple devices. If you're on Android or split your life across Android and Apple devices, 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 bigger PK curve library. Regimen says it draws half-life curves for 150+ compounds. OptiPin models testosterone, estradiol, DHT and GLP-1s in depth, plus 40+ further compounds. If breadth of curves matters more to you than calibration, Regimen covers more.

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.

A bigger multilingual website. Regimen's site and guides come in seven languages. OptiPin's site covers four, which match its four in-app languages; Regimen's App Store listing names English as its app language.

Niche extras. 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 iCloud Sync through your own iCloud account. Regimen is account-based with cloud sync – your data lives on its servers, and its App Store privacy label lists health data, email, name, photos and user/device identifiers as collected and linked to your identity. Cloud sync is genuinely useful; the trade-off is custody of your dosing history.

Does Regimen run on Android?

Yes – iOS and Android (plus iPad and Apple Silicon Macs), with cloud sync across devices, Apple Health on iOS and Google Health Connect on Android. Its own comparison page also says it runs on the web; we could not find a web app. OptiPin is iOS-only. If you're on Android, 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 150+ compounds from published 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.

Is OptiPin cheaper than Regimen?

Yes. On the US App Store on 29 September 2026, OptiPin Premium was $4.99/month or $39.99/year and Regimen Premium was $7.99/month or $49.99/year. Regimen's own page agrees. Both are free for one compound with no time limit and no card. Both also offer a 14-day trial.

Is OptiPin harder to learn than Regimen?

OptiPin has more surface area, and Regimen's comparison page is fair to say so. It ships 200+ 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 (as it read on 29 September 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. Its feature table is out of date on vial tracking, progress photos, insights, compound count and half-life curves; the dates are 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, as it read on 29 September 2026) – source for every Regimen quote and concession on this page
• helloregimen.com – platform support, Signals engine, website languages, 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 and the public version history that dates each feature
• 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 (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 29 September 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.