Healthcare services · Obesity and metabolic care
Alfie
A New York telehealth clinic that used an AI model called ObesityRx to match patients with weight loss medications and behavior changes. It raised a small pre-seed round in 2023 and was acquired by a competitor, knownwell, in June 2024.
A $120 a month clinic, run over video
Alfie did not run its own pharmacy or ship its own drugs. It was a virtual clinic. A patient signed up, handed over medical records, and got sent to Labcorp or Quest Diagnostics for metabolic bloodwork. That data fed a proprietary algorithm the company called ObesityRx, which combined the labs, intake surveys and history into a recommended mix of medication, nutrition, exercise and sleep changes. A clinical team, including nurse practitioners and doctors, reviewed the recommendation before it reached the patient. Out of pocket, the program cost $120 a month. In eight states, including New York, California, Texas and Florida, it billed insurance directly.
The problem it picked
Alfie launched into the biggest reshuffle obesity care had seen in a generation. GLP-1 drugs like Ozempic and Wegovy were pulling patients toward telehealth weight loss clinics by the millions, and a wave of venture money followed, from WeightWatchers rebuilding itself around the drugs to newer entrants like Noom, Calibrate and Found. Alfie’s pitch was narrower: GLP-1s do not work, or are not appropriate, for every patient, so a platform that could sort patients into the right combination of drugs and behavioral change, rather than defaulting everyone to the same injection, had a case to make to skeptical payers and employers.
Founder and CEO Alexander Singh described the idea plainly. “We use a proprietary AI clinical decision support tool that allows us to understand what underlying issues [patients have] that is causing them to gain weight, and then recommend a combination of precision medicine and behavioral change that is unique to each patient to help them sustainably lose weight,” he told MedCity News in July 2023.
Founders and early backers
Singh led Alfie as CEO with Rohit Rustagi as COO, according to the company’s June 2023 funding announcement. Singh had built a company before: his Y Combinator founder bio describes him as having “formerly built MIST Health (CV spinal diagnostics)” before Alfie, and having spent time as an Investment Partner at Pioneer Fund and a technology consultant at the FDA during the Covid pandemic.
The June 2023 pre-seed round, $2.1 million, was led by Y Combinator and Nina Capital, with Goodwater Capital, Phoenix Investment Club and unnamed angel investors participating, according to FinSMEs and MedCity News. The company’s own Y Combinator page adds Air Force Ventures to the investor list and names one angel by description, not name: “the founder of OpenTrons.” Independent coverage of the same round did not mention Air Force Ventures.
Acquired eighteen months after launch
On June 20, 2024, Boston-based knownwell announced it had acquired Alfie. Knownwell is a weight-inclusive primary and metabolic care company backed by Andreessen Horowitz Bio and Health and Flare Capital Partners, which had just closed a $20 million Series A six months earlier and had raised $24.5 million in total, per Business Insider. Neither company disclosed the price. Singh joined knownwell as head of analytics. Alfie’s standalone app and its affiliated clinics were shut down; the company said as much on its own website, as MobiHealthNews reported at the time.
Knownwell folded ObesityRx into its own care model rather than running it as a separate product. Founder and CEO Brooke Boyarsky Pratt told Fierce Healthcare the technology would act as a clinical co-pilot, surfacing research-based suggestions to knownwell’s own doctors, who would still decide the care plan.
What is proven, and what is still claimed
| Evidence | What the record shows | Source type |
|---|---|---|
| Effectiveness claim | The company said its program was “shown to be 2x more effective than standard prescription medication and 5x more effective than habit change alone,” on its Y Combinator page. No underlying study, sample size or publication was found. | Company-stated |
| Acquirer’s assessment of that evidence | Knownwell CEO Brooke Boyarsky Pratt said in an interview that “Alfie has compelling research, but it’s not peer-reviewed and it’s not double-blinded, that suggests that their ability to prescribe older medications, so the combination of medications as opposed to just GLP-1s, outperforms the clinical research.” | Interview |
| Peer-reviewed publications | None found for Alfie Health or ObesityRx in a PubMed search. | Not found |
| Registered clinical trials | None found on ClinicalTrials.gov. | Not found |
| FDA records or warning letters | No 510(k), PMA or FDA warning letter naming Alfie Health or ObesityRx was found, despite the broader FDA scrutiny of compounded GLP-1 drugs sold by other telehealth clinics. | Not found |
| Payer and clinical relationships | The company said it billed insurance in Maryland, Virginia, New York, New Jersey, California, Texas, Florida and Washington, D.C., and that it worked with an unnamed cardiology group and an unnamed self-funded employer client. | Company-stated |
| Pre-seed funding | $2.1 million announced in June 2023, led by Y Combinator and Nina Capital, with Goodwater Capital, Phoenix Investment Club and angel investors, reported independently by FinSMEs and MedCity News. | Independent |
| Investor list conflict | The company’s own Y Combinator page names Air Force Ventures as a backer; independent coverage of the same round does not. | Differs from reporting |
| SEC Form D | No Form D under Alfie Health’s own name was found in EDGAR. Several unrelated entities also named Alfie (Alfie Investors LLC, Alfie Private Line of Credit LLC, and others) filed Form Ds over the years; nothing ties them to this company, and they are excluded here. | Not found |
Read plainly, Alfie’s clinical claims never left the company’s own marketing. Its own acquirer, in the act of buying it, said openly that the research behind it was neither peer-reviewed nor double-blinded. That did not stop the deal. Knownwell bought the software, the data pipeline and the founder, not a body of published evidence, and said so.
What to watch
- Whether knownwell publishes any peer-reviewed research using the ObesityRx approach, something Boyarsky Pratt said the company wanted to do.
- Whether knownwell discloses the price of the Alfie acquisition; neither company has as of this writing.
- What becomes of Alfie’s payer contracts and the cardiology group and employer relationships it described, now folded into knownwell.
- Alexander Singh’s next moves; his Y Combinator bio now lists him investing in healthcare companies at Yosemite, an oncology-focused venture firm.
In their words
“We use a proprietary AI clinical decision support tool that allows us to understand what underlying issues [patients have] that is causing them to gain weight, and then recommend a combination of precision medicine and behavioral change that is unique to each patient to help them sustainably lose weight,”
Alexander Singh, CEO and co-founder, to MedCity News, July 2023 · Independent
“Having a program that is really focused on not just the precision of which medications may work the best, but also the precision of which behavioral lifestyle changes (exercise, diet, sleep, etc.) will work the best … is really important,”
Alexander Singh, to MedCity News, July 2023 · Independent
“In the long term, it’s those behavioral changes in combination with the medications that are delivering sustainable results.”
Alexander Singh, to MedCity News, July 2023 · Independent
“This acquisition by knownwell helps us deliver on our mission to provide patients in need with best-in-class obesity management,”
Alexander Singh, in the acquisition announcement, June 20, 2024 · Company release
“knownwell’s leadership, clinical expertise, and hybrid model make them a leader in obesity management, and their hybrid model will strengthen our high-touch care approach to improve patient results.”
Alexander Singh, in the acquisition announcement, June 20, 2024 · Company release
“We knew we had to move to an AI-driven clinical decision support model for our physicians, because it’s just too many disease states,”
Brooke Boyarsky Pratt, knownwell founder and CEO, to Business Insider, June 2024 · Independent
“Alfie has compelling research, but it’s not peer-reviewed and it’s not double-blinded, that suggests that their ability to prescribe older medications, so the combination of medications as opposed to just GLP-1s, outperforms the clinical research.”
Brooke Boyarsky Pratt, to Fierce Healthcare, June 2024 · Independent
“Our program has been shown to be 2x more effective than standard prescription medication and 5x more effective than habit change alone.”
Company statement, Y Combinator company page · Company-stated
Related companies
Sources
- CompanyAlfie: Democratizing access to precision weight loss medications
- IndependentAlfie Health Raises $2.1M for AI-powered Weight Loss Platform
- IndependentAlfie Health Raises $2.1M in Funding
- IndependentKnownwell acquires Alfie Health to integrate AI into its primary and obesity care services
- IndependentExclusive: A16z-backed Knownwell is buying AI-powered Alfie Health to supercharge its obesity care
- IndependentKnownwell Acquires Competitor to Expand Access to Comprehensive Obesity Care
- Independentknownwell acquires Alfie Health to enhance metabolic health offerings
- IndependentObesity care startup knownwell buys an AI weight loss platform
- Companyknownwell Acquires Alfie Health, Builds C-Suite to Expand Access to Tailored, Cost-Effective Obesity Treatment Enabled by AI
Profile researched and written by Healthcare Discovery. Last updated September 29, 2026.
