Clip-on cap that records every insulin pen dose for your diabetes clinic
TL;DR Pentally is a Bluetooth cap that fits onto the insulin pens people in India already use and notes the time of every injection. Diabetes clinics and insulin makers' support programmes pay for it, because a doctor adjusting doses today is guessing whether the patient took the last ones.
India has about 101 million adults with diabetes, plus 136 million with prediabetes[1]. Many eventually need insulin, and most of them inject at home with no record anyone can check. In one audit of 748 insulin users at an urban Indian clinic, two in three used pens, 12.57% had lipohypertrophy (lumpy fat from injecting in the same spot), and 72.19% reused needles[2].
So when sugars stay high, what does the endocrinologist go on? Either the dose is wrong or doses are being missed, and the patient's memory is the only evidence. I found no Indian figure for missed insulin doses, which tells you how little gets measured.
First, the regulatory bit - Pentally does dose logging and reminders only. It records when the pen was used and shows that history to the patient and the clinic. It does not calculate or recommend a dose. Even so, a pen accessory is likely to count as a medical device under the Medical Devices Rules 2017, so plan for a CDSCO licence and confirm the class with a regulatory consultant first.
The cap replaces the plastic cap on common reusable and disposable pens. Each time it comes off and goes back on, it stamps the time and syncs to a phone, and the patient gets a reminder if a basal dose looks missed. Before each review the clinic sees a two-week timeline beside the patient's glucose readings and can spot skipped evening doses at a glance.
The seed pitched an integrated smart insulin patch. That tech has only worked in mice so far, and a 2026 patent review puts it 5–10 years from human use[3][4]. So Pentally keeps the goal of better insulin management at home and swaps the mechanism for one that can ship now.
The user is an adult injecting insulin several times a day, but that person rarely pays. Abroad, one smart-cap team planned to give its cap free to users and charge insurers, drug makers and clinician networks[5]. In India, the first buyers to test are diabetes clinic chains that sell care programmes and insulin makers running patient-support schemes. I found no Indian price for a smart cap, so pricing is an open question for the sprint.
CDSCO brought every class of medical device under licensing between October 2022 and October 2023, and in July 2026 it listed a guidance document on medical device software[6]. The rules for a connected accessory are clearer than they were three years ago. Radio approval for Bluetooth devices is a self-declaration at ₹10,000 per model[7], and cheap Bluetooth chips keep the bill of materials low.
No public figure exists for connected insulin caps in India. The nearest number is the pen market itself - One market research firm puts India's insulin pen market at US$249.5M in 2025 (about ₹2,413 Cr), with reusable pens holding 72.14%[8].
Treat that as a neighbour. The count that matters, people on multiple daily injections who see a specialist, has no published estimate.
Nobody sells a smart pen cap in India that I could find. In the US, one system won FDA clearance in 2021 for a cap that recommends doses from CGM data[9], which put it in a stricter regulatory lane. A Danish company sells a cap that records dose timing and size, mainly to healthcare companies[10]. The gap is a logging-only cap that fits Indian pen models and plugs into how Indian clinics already work.
| Difficulty | Hard (60/100) |
| Starting capital | ₹2–3.7 Cr |
| Time to launch | 12–18 months |
The electronics are simple. Fit isn't, because the cap must sit snugly on several pen designs from different makers without changing how the pen works. Then come the device licence, a quality system and a usability study. Clinics also need the data inside the review they already run or nobody will open it.
Yes. A pen accessory is likely a medical device, so plan for a licence before you sell.
Building this outside India? The categories above usually have a local equivalent, so check with your own regulator.
Never let AI suggest or change an insulin dose. Pentally does logging and reminders only, and dosing stays with the doctor and the patient.
Want to work out the AI layer for Pentally? Talk to Yash →
Here's what can go south -
This suits a founder with medical-device and manufacturing experience who's happy to sell to clinics and pharma before patients. If you're hoping to build a patch or an AI dosing engine on seed money then it's a poor fit, honestly. I'd prove one thing first - that a clinic changes its treatment decisions once it can see dose timing.
My estimate is ₹2–3.7 Cr, covering hardware design, licensing, testing and the first production run. The kit has the detail.
Very likely. A pen accessory probably counts as a medical device, so plan for a CDSCO licence, and a Bluetooth cap needs WPC approval too.
Yes, insulin pens are used everywhere. Device and health-data rules vary by country though, so check with your local regulator.
The free Pentally validation kit has the line-by-line capital breakdown, the effort scoring, the device-licence and radio checklist, a 14-day validation sprint with pass/fail targets, a 90-day launch plan, 10 interview questions for patients and clinics, and 5 assumptions to test. Download the kit →
Thinking about building Pentally or something close to it? The make-or-break bit is getting the device class right and a cap that fits India's common pens. If you need a hand, you know where to find me. Talk to Yash →
For illustration only. Names are fictional and ideas hypothetical; sourced facts are real but may be out of date. Nothing here is legal, financial or professional advice, and Yash Khatri is not personally liable for any use of it. Read the full disclaimer.