Digital health · Diabetes management
DoseDr
A Y Combinator company whose app told people with insulin-treated diabetes what to inject, with a doctor watching the data behind the screen. It never held an FDA clearance, and it stopped operating at the end of 2019.
The clinic in the old department store
After Katrina, the Lord and Taylor building in downtown New Orleans was empty. Somebody retrofitted it into a free clinic for people without insurance, and Tulane and LSU residents worked it in rotation. Dustyn Williams was one of them. He was there one week in five.
A man came in newly diagnosed with insulin-treated diabetes. Williams could not see him again for more than a month, so he wrote out a set of personalized instructions by hand and sent him home with them.
“Five weeks later he returned to clinic having successfully titrated himself.”
That is the origin story Williams gave an interviewer in 2018, and the whole company follows from it. “If a patient could do this, on his own, with my hand-written instructions, surely this could be done with any patient with the right tool.”
The gap between appointments
The gap DoseDr aimed at is real and well documented. A person on insulin sees a primary care provider for roughly two and a half hours a year, by the company’s own count and by the account of a hospital diabetes educator who wrote about the product. The rest of the year, the disease is managed by the patient. Doses that need to move do not move, or move once a quarter, in a clinic room.
“Most patients get only two and a half hours with their doctor per year, so the reality is that chronic diseases are mostly treated by the patient,” Williams said in a 2018 company release.
Several companies attacked that gap, and the serious ones went through the FDA. Sanofi’s My Dose Coach, Hygieia’s d-Nav and Glytec’s Glucommander all hold 510(k) clearances under one class II product code, Calculator, Drug Dose. Hygieia’s system was tested in a randomized trial of 181 people with type 2 diabetes, published in 2019 and funded by the National Institutes of Health.
Three founders, one of them the doctor
Y Combinator’s company page lists three former founders: John Sanders as founder and chief executive, Marlon Castillo as a founder, described there as a “Former energy trader, currently building healthcare and wellness companies,” and Dustyn Williams. Williams is the one who shows up in the press, as co-founder and chief medical officer.
His day job was medicine and teaching. Yale undergraduate, Tulane medical school, board certified internal medicine hospitalist at Baton Rouge General. He also founded OnlineMedEd, a study platform for medical students, which Archer Review acquired in March 2025.
Demo day, then a hospital
DoseDr launched out of Y Combinator’s Winter 2016 batch. TechCrunch covered it on the second demo day, in one paragraph: “Earlier this year, DoseDr started a pilot program with five clinics and 50 high-risk patients. In the first month of the program, DoseDr was able to bring 93% of patients into the safe range.”
The company’s own launch post said the service was live in California and Louisiana, with plans for New York, Florida and Illinois by mid year. The one named customer in the record is CHRISTUS St. Frances Cabrini Hospital, a 281 bed hospital in Alexandria, Louisiana. No federally qualified health center is named in any source located for this profile.
In March 2018 the company said it had extended the platform from diabetes to hypertension, with heart failure and COPD modules slated for the following month. That release is the last substantial public statement DoseDr made.
What is proven, and what is still claimed
| Evidence | What the record shows | Source type |
|---|---|---|
| FDA status | Searches of the FDA 510(k), PMA and device registration and listing databases return no match for DoseDr as applicant, device name or proprietary name, checked September 2026. | Public record |
| Cleared comparators | Sanofi My Dose Coach, K163099, cleared Mar 22, 2017, and K171230 on May 26, 2017. Hygieia d-Nav System, K181916, Feb 4, 2019. Glytec Glucommander, K152300, Aug 4, 2017, with K061110 in 2006 and K254102 on May 27, 2026. All under 21 CFR 868.1890, class II. | Public record |
| Trials and literature | No study on ClinicalTrials.gov. No PubMed record for DoseDr, searched September 2026. No NIH or NSF award found. | Not found |
| Hospital pilot, as announced | March 2018 release: average A1c fell from 9.6 to 6.3 in three months, adherence 88 percent, and of 14,460 app interactions one was symptomatic hypoglycemia. The release calls it “a recently published pilot study.” | Company-stated |
| Same pilot, hospital account | A November 2017 article by the CHRISTUS diabetes educator reports 76 percent retention, 100 percent daily engagement among those retained, and A1c falling from 8.6 to 6 over 90 days. | Differs from release |
| Same pilot, founder account | A May 2018 interview describes two pilots and an average A1c move from 9.3 to 6.4 in three months. | Differs again |
| The published study | No paper matching the described pilot appears in PubMed. The three accounts of it do not agree on baseline, endpoint or cohort. | Not found |
| Product claim versus terms | Marketing said patients enter a blood sugar and the app tells them how much insulin to take. The terms of use archived in August 2016 said: “DoseDr does not offer medical advice or diagnoses, or engage in the practice of medicine.” | Claim differs |
| Operating status | Last archived working homepage Dec 14, 2019. PitchBook records out of business Dec 1, 2019. Y Combinator lists the company as inactive. By August 2025 the domain redirected to a domain reseller listing. | Public record |
Read plainly: every outcome number attached to DoseDr comes from the company or from the hospital that ran the pilot, and the three surviving versions of that pilot disagree. Nothing was registered, published or submitted to a regulator. The comparators that did all three are still on the market. A real clinical idea, tested on real patients in Louisiana, left behind no evidence a third party can audit.
What to watch
- The pilot the company called published. As of September 2026 no matching paper is indexed in PubMed, and the numbers differ across all three published accounts.
- The product code. Glytec cleared a new Glucommander submission under 21 CFR 868.1890 in May 2026, so the pathway remains live.
- The founders. Dustyn Williams sold OnlineMedEd to Archer Review in March 2025. No successor company for John Sanders or Marlon Castillo appears in the records searched.
- The domain. dosedr.com has pointed at a reseller listing since at least August 2025, which is the clearest public marker of the end.
In their words
“Five weeks later he returned to clinic having successfully titrated himself.”
Dustyn Williams, MD, co-founder and chief medical officer, Authority Magazine interview, 2018 · Interview
“If a patient could do this, on his own, with my hand-written instructions, surely this could be done with any patient with the right tool.”
Dustyn Williams, Authority Magazine interview, 2018 · Interview
“I wanted to prove that it wasn’t the people of Louisiana that failed, it was the system that failed the people of Louisiana”
Dustyn Williams, Authority Magazine interview, 2018 · Interview
“Most patients get only two and a half hours with their doctor per year, so the reality is that chronic diseases are mostly treated by the patient,”
Dustyn Williams, March 2018 company release · Company release
“DoseDr empowers and motivates patients to optimally self-manage their conditions.”
Norma “Marie” Myers Simpson, BSN, RN, CDE, CHRISTUS St. Frances Cabrini Hospital, March 2018 company release · Partner-stated
“In the first month of the program, DoseDr was able to bring 93% of patients into the safe range.”
TechCrunch, Y Combinator Winter 2016 demo day coverage, March 2016 · Independent
“DoseDr does not offer medical advice or diagnoses, or engage in the practice of medicine.”
DoseDr terms of use, archived August 2016 · Company
“Healthcare professionals should exercise substantial caution in recommending unregulated dose calculators to patients and address app safety as part of self-management education.”
Huckvale and colleagues, BMC Medicine, 2015 · Peer reviewed
Related companies
Sources
- Public recordFDA 510(k) database, no match for DoseDr as applicant or device name
- Public record510(k) K163099, My Dose Coach, Sanofi
- Public record510(k) K181916, d-Nav System, Hygieia
- Public record510(k) K152300, Glucommander, Glytec
- Public recordClinicalTrials.gov and PubMed searches for DoseDr, no results
- Public recordInternet Archive capture history for dosedr.com, last working homepage Dec 14, 2019
- IndependentHere are the 59 startups that demoed at Y Combinator Winter ’16 Demo Day 2
- IndependentDoseDr company profile: valuation, funding and investors
- IndependentDoseDr wiki entry listing investors and advisers
- Peer reviewedSmartphone apps for calculating insulin dose: a systematic assessment
- Peer reviewedInpatient and outpatient technologies to assist in the management of insulin dosing
- Peer reviewedAutomated insulin dosing guidance to optimise insulin management in patients with type 2 diabetes
- InterviewAdvances in technology are improving chronic disease management through real time patient monitoring
- CompanyDoseDr telemedicine platform expanded for use treating all chronic diseases
- CompanyDoseDr (YC W16) helps people with diabetes control their treatment in real time
- CompanyDoseDr company page listing founders, team size and status
- CompanyDoseDr terms of use and homepage
- PartnerA better prescription for diabetes care
Profile researched and written by Healthcare Discovery. Last updated September 29, 2026.
