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Digital health · Chronic insomnia

Stellar Sleep

A subscription app delivering the psychology sleep clinicians use, built by two people who could not get an appointment. It has one registered trial, sponsored by someone else, and no FDA clearance.

Founded2021, as a venture at Harvard Innovation Labs
BatchY Combinator, Summer 2023
Legal nameTwenty Nights, Inc
FoundersGeorge Wang and Edrei Chua
Seed round$6M announced Feb 6, 2024
FDANo 510(k) or PMA on record
Registered trialNCT05991492, sponsor Brigham and Women’s Hospital
Headcount13 as of Aug 2026, per Tracxn

Seven hours in bed, four hours asleep

George Wang had just been promoted. At McKinsey, engagement manager is the rung where you stop doing the analysis and start owning it, and the job followed him home. He protected seven hours in bed every night and slept four or five of them. The thoughts did not stop when the light went off: unfinished tasks, work to hand out, how the data fit together.

Most of his team were MDs and PhDs. They told him, unofficially, that this was chronic insomnia, and that the treatment was cognitive behavioral therapy for insomnia, known as CBT-I.

So he went looking for it. “Armed with that knowledge, I went around to different CBT-I providers in the area but kept getting turned away”, he told his investor Parul Singh in 2024. The clinics were closed to new patients, or the wait was three to six months.

He took the certification course himself instead and ran the protocol on his own sleep. “I’m not a trained psychologist, but I used the methods on myself, and they worked when nothing else had”, he said. That sentence is the company in miniature, and it is also the reason to read its evidence closely.

A first line treatment almost nobody can reach

The guidance is not ambiguous. In May 2016 the American College of Physicians recommended CBT-I as the first line treatment for adults with chronic insomnia, ahead of medication. In December 2020 an American Academy of Sleep Medicine guideline made one strong recommendation, for CBT-I, and told clinicians that sleep hygiene is not a stand alone therapy. In April 2026 an AASM task force weighing drugs against therapy landed in the same place.

The bottleneck has never been the evidence. It is the workforce. Stellar Sleep puts the ratio on its mission page: “There are more than 10,000 people with chronic insomnia for every clinician trained to treat it.”

That gap is real, and it is the case for software. It is also where the reasoning has to slow down. CBT-I is first line care, but that status belongs to the therapy, earned across decades of trials. It does not transfer automatically to any product that says it delivers the therapy. Two insomnia apps have been through the FDA on exactly that question. Stellar Sleep has not.

Two insomniacs build the thing they wanted

Wang has a biology degree and worked in precision medicine research before consulting. His co-founder Edrei Chua led engineering teams at Google across health and AI, and describes his own insomnia in terms of brain wave scans he paid for and hours lost to Hacker News at 3am.

They started in 2021 as a venture at the Harvard Innovation Labs, went through Y Combinator in Summer 2023 with a team of five, and launched publicly that August. Nine months later they told YC they had passed $1 million in annual run rate. In February 2024 Initialized Capital led a $6 million seed, joined by Y Combinator, Lombardstreet, Switch, Moonfire, Scrum, 8vdx and Goodwater. It was the first institutional money in.

The product asks five to ten minutes a day, and its named techniques are the standard ones: sleep restriction, stimulus control, cognitive restructuring. At launch it cost $60 a month; the FAQ now says the basic program starts at $188. The safety copy is careful, which matters because sleep restriction has a real cost: the curriculum “uses sleep restriction and consolidation, which may cause daytime sleepiness until sleep has been regulated”, and people with bipolar disorder, epilepsy or untreated sleep apnea are told to ask a clinician first.

The app becomes a clinic

By 2026 the business had changed shape. The website says “Today we operate the largest network of insomnia clinicians in the US.” That claim carries an asterisk and no published substantiation. Patients are routed to the app or to a matched specialist who bills insurance. Running the network is an in house system called Rhythm, where “AI agents do the routine work; our team governs them, so our clinicians focus on care.” Agents verify eligibility, code the session, submit the claim and draft the note; a clinician reviews and signs.

What is proven, and what is still claimed

Consumer track. Stellar Sleep is sold as a subscription, not prescribed as a device. Nothing requires a clearance and nothing stops it seeking one, but the effect is that its claims have never been reviewed by a regulator or a journal.
EvidenceWhat the record showsSource type
FDA statusNo 510(k) and no PMA under Stellar Sleep, Twenty Nights, Inc or Merlin Collective, LLC as of Sep 24, 2026. The registered trial record marks the study as not involving an FDA regulated device.Public record
Registered trialNCT05991492, sponsored by Brigham and Women’s Hospital, names Stellar Sleep as “a new digital CBT-I application”. Randomized crossover, unmasked, enrollment 60, one Boston site, primary outcome change in Insomnia Severity Index at 6 to 8 weeks. Started Feb 13, 2024, active and not recruiting, no results posted.Public record
Who paid for the trialThe Massachusetts eHealth Institute says a $100,000 grant from its 2022 provider innovation challenge paid for a placebo controlled study run by Dr. Sogol Javaheri at Brigham and Women’s Hospital.Public record
Trial as described by the companyThe Y Combinator page claims “a year-long clinical study running with Harvard Medical School / Brigham & Women’s Hospital paid for by the State of Massachusetts and the US Department of Commerce”. The registry lists a 60 patient pilot sponsored by the hospital, with no collaborators named.Differs from registry
The headline efficacy number“a clinical assessment of 500 users found Stellar Sleep to be 50% more effective than sleeping pills” appears in the February 2024 release and most coverage since. No protocol, comparator drug, endpoint or publication has been identified.Company-stated
Peer reviewed papersNo publication on Stellar Sleep found in PubMed searches for the product or its legal entities as of Sep 24, 2026.Not found
Cleared comparatorsSomryst, Pear Therapeutics, 510(k) K191716, decision Mar 23, 2020. Sleepio, Big Health, 510(k) K233577, decision Aug 5, 2024. Both sit under 21 CFR 882.5801. Somryst was evaluated in two randomized trials of more than 1,400 adults; Pear went bankrupt in 2023 and Somryst sold for $3.9 million.Public record
Price on the record$60 a month at launch in 2024, per the release and independent coverage. The FAQ states the basic program starts at $188.Claims differ

Read plainly: there is one real study, it belongs to Brigham and Women’s Hospital, a state grant paid for it, it enrolls 60 people, and it has not reported. Everything else offered as evidence is a number the company produced about itself.

What to watch

  • Results from NCT05991492, whose primary completion was estimated for July 2026.
  • Whether the 500 user assessment is ever written up with a method and a comparator.
  • Reimbursement. CMS created codes G0552 to G0554 in the 2025 Physician Fee Schedule for FDA cleared digital mental health treatments, and nine products qualify. Stellar Sleep is not one, which makes clearance a business decision as well as a clinical one.
  • What the clinician network actually is: how many clinicians, which payers, and who carries clinical responsibility when an agent drafts the note.
  • A funding round. Nothing has been announced since the 2024 seed.

In their words

“Armed with that knowledge, I went around to different CBT-I providers in the area but kept getting turned away”

George Wang, co-founder, Initialized Capital founder interview, 2024 · Interview

“I’m not a trained psychologist, but I used the methods on myself, and they worked when nothing else had”

George Wang, Initialized Capital founder interview, 2024 · Interview

“However, your doctor is choosing between giving the patient prescription drugs or putting them on a six-month long waiting list.”

Edrei Chua, co-founder, to TechCrunch, 2024 · Independent

“In addition to the waiting list, the cost and time commitment involved meant that out-of-pocket sleep therapy was out of reach for most.”

George Wang, seed funding release, February 2024 · Company release

“No one values sleep as much as those who can’t get it. The treatment options are so limited that these founders got trained as sleep therapists to treat themselves”

Parul Singh, partner, Initialized Capital, in the February 2024 release · Company release

“The multicomponent treatment, cognitive behavioral therapy for insomnia, is the most supported therapy.”

Jack Edinger, PhD, lead author, AASM behavioral treatment guideline, 2020 · Guideline

“Our analysis suggests that CBT-I by itself is the most efficacious first-line treatment for insomnia.”

Daniel J. Buysse, MD, lead author, AASM combination therapy guideline, 2026 · Guideline

“When building a mental health company, it’s crucial to stay patient-centered and focus on creating a product that is clinically beneficial, not just engaging.”

George Wang, Initialized Capital founder interview, 2024 · Interview
Stellar Sleep funding profile on HVCFHealthcare Venture Capital Fund

Related companies

Sources

  1. Public recordClinicalTrials.gov NCT05991492, digital CBT-I application studyBrigham and Women’s Hospital · updated Jan 30, 2026
  2. Public recordFDA 510(k) K191716, SomrystFDA · decision Mar 23, 2020
  3. Public recordFDA 510(k) K233577, SleepioFDA · decision Aug 5, 2024
  4. Public recordSEC EDGAR full text search, three company names, no documentsSEC · Sep 24, 2026
  5. Public recordPubMed searches for Stellar Sleep, no matching papersNLM · Sep 24, 2026
  6. Public recordManagement of Chronic Insomnia Disorder in Adults, ACP guidelineAnnals of Internal Medicine · May 3, 2016
  7. Public recordBehavioral and psychological treatments for chronic insomnia, AASM guidelineJournal of Clinical Sleep Medicine · Feb 2021
  8. Public recordDigital Solution Poised to Transform Sleep HealthMassachusetts eHealth Institute · Apr 17, 2024
  9. IndependentStellar Sleep app gets initial funding for chronic insomniaTechCrunch, Christine Hall · Feb 6, 2024
  10. IndependentDigital Insomnia Solution Raises $6M to Expand App ReachSleep Review · Feb 9, 2024
  11. IndependentNew guideline recommends combined therapies for insomniaNews-Medical · Apr 21, 2026
  12. Independent$23.7M Secured to Scale FDA-Cleared Digital Sleep TreatmentsSleep Review · Feb 12, 2026
  13. CompanyLaunch YC: Stellar Sleep, Break the insomnia cycle tonightY Combinator · Sep 24, 2026
  14. CompanyHome, mission, platform, FAQ and reviews pagesstellarsleep.com · Sep 24, 2026

Profile researched and written by Healthcare Discovery. Last updated September 29, 2026.