Digital health · Adult ADHD
Inflow
A self help app teaching cognitive behavioral therapy skills to adults with ADHD. Built in London, funded to a reported $14 million, tested in one open study and one randomized trial, acquired by Cerebral in March 2026.
Five minutes a day
You download Inflow, answer a short assessment, and start a seven day free trial. After that it costs $22.49 a month without coaching or $47.99 with it, or $95.99 and $199.99 a year, per an independent review published in March 2025. What arrives each day is a lesson of about five minutes, narrated by the company’s co-founder and clinical director, a New York psychologist named George Sachs.
The lessons teach CBT techniques adapted for ADHD: breaking a task into pieces, catching the thought that precedes avoidance, building a routine that survives a bad week. Around them sit a community feed, live coworking rooms and an AI companion called Quinn.
The app’s own help pages draw a hard line around all of it. Asked whether Inflow can diagnose ADHD or prescribe medication, the company answers: “No. Inflow is not a diagnostic tool and does not offer clinical services or medical treatment.” Asked whether it replaces therapy or drugs: “Inflow isn’t meant to replace medication or in-person therapy, these options work well for many people, and we fully support them.”
That line is the whole regulatory story, and not everyone around the company has drawn it in the same place.
The waiting list problem
The case for the category is not in dispute. The randomized trial of the app opens with it: “Cognitive behavioral therapy (CBT) is an efficacious treatment for adult ADHD, yet access and availability concerns limit scalability.” The therapy works. Too few clinicians deliver it, and those who do cost money and keep waiting lists.
How many adults are waiting is contested. Cerebral’s release cites CDC figures putting adult ADHD prevalence near 6.0 percent in 2023, with roughly 36.5 percent of diagnosed US adults getting no formal treatment. Behavioral Health Business put US prevalence at 3.5 percent. MobiHealthNews cited NHS figures near 2 percent of UK adults. Inflow’s lead investor and much of the coverage used a larger number: 10 percent of the global population.
Two computer scientists and a psychologist
Sebastian Isaacs and Levi Epstein met while completing masters degrees in computer science at Imperial in London, according to Octopus Ventures. Epstein had been a product manager at Babylon Health. They brought in Sachs, who runs the Sachs Center in New York, has written four books on ADHD, and was diagnosed himself late in life.
The UK register records the beginning precisely. Get Inflow Ltd was incorporated on May 27, 2020 as ADYNN LTD and renamed that October. Its registered activity is not health care but SIC code 62090, other information technology service activities. Isaacs was the first director, Epstein joined that October, and both were people with significant control until October 26, 2021, when control passed to a Delaware parent, Inflow Holdings, Inc. That parent had registered a UK establishment a month earlier and told Companies House its object was to “Provide accesible cbt treatment”. The spelling is the register’s.
Money, then evidence, then an exit
Inflow raised $680,000 in 2020 from Rhythm VC and angels, went through Y Combinator in the summer of 2021, and announced a $2.3 million seed led by Hoxton Ventures in January 2022. The first paper landed that August. In November 2022 it bought Lina Health, a New York telehealth clinic with close to 1,000 cumulative members, to add clinician diagnoses. In January 2023 it announced an $11 million Series A led by Octopus Ventures, and the firm’s health partner, Will Gibbs, took a board seat.
Then the trail thins. Isaacs resigned as a director of the UK company on October 31, 2025. The randomized trial appeared in 2026. On March 24, 2026, Cerebral announced it had bought Inflow, terms undisclosed, with Epstein named as sole chief executive. Both platforms, the companies said, will keep operating separately.
What is proven, and what is still claimed
| Evidence | What the record shows | Source type |
|---|---|---|
| Open feasibility study | PLOS Digital Health, Aug 2022. Seven weeks, no control group. 241 consented, 205 enrolled, 108 finished the week 7 survey, a 52.7 percent retention rate. Median 3.86 sessions a week. Two co-authors are Inflow co-founders with an ownership interest, and the company gave participants free access. | Public record |
| Randomized trial | Journal of Attention Disorders, 2026, by Antshel, McBride and Knouse. 154 assessed adults, randomized to 8 weeks of the app or a waitlist. Significant effects on inattentive symptoms, hyperactive-impulsive symptoms and ADHD quality of life, but not on functional impairment. The authors write: “The confidence in our results is limited by our use of a waitlist control design.” | Public record |
| Which app was tested | The abstract calls it a CBT-informed health app and never names it. The conflict statement names Inflow Holdings, Inc., where an author is a paid consultant holding stock options. Cerebral describes an 8 week trial with matching results. | Inferred from record |
| FDA and registries | No 510(k), PMA or De Novo record for Inflow or Inflow Holdings, Inc. in FDA device databases, and no entry in ClinicalTrials.gov, searched September 23, 2026. | Not found |
| How it is described | Inflow’s FAQ says it does not offer clinical services or medical treatment, and its App Store category is Health & Fitness. Cerebral calls it a personalized ADHD digital therapeutic app. Octopus Ventures framed it as a service for people “looking for treatment other than powerful medication with far-reaching side effects”. | Claims diverge |
| Prevalence figure | Investor and press accounts repeat that ADHD affects about 10 percent of the global population. The CDC figures in Cerebral’s own release put US adult prevalence near 6.0 percent, and NHS figures put UK adults near 2 percent. | Differs from cited data |
| Reach | Cerebral says Inflow “has been used by hundreds of thousands of people globally”. An independent review counted more than 100,000 Google Play downloads by August 2024. Nothing is audited. | Company-stated |
| Billing complaints | Trustpilot rated getinflow.io 3.3 out of 5 in a January 2026 capture, with repeated reports of charges after cancellation. An independent reviewer found the same pattern across Apple, Google and Reddit while rating the app 4.5 of 5. | Independent |
| UK accounts | Get Inflow Ltd files total exemption full accounts as a small company, latest to December 31, 2025. They carry no profit and loss account, so UK revenue is not public. | Public record |
Read plainly: Inflow carries more published evidence than most wellness products and less than a regulated treatment. The open study showed people would use it. The trial showed self reported symptom and quality of life gains against a waitlist, a control that measures expectation as well as effect, and no gain on functional impairment. The company says it does not treat. Its lead investor and its acquirer have both used the language of treatment, and under the wellness policy that language is part of how intended use gets judged.
What to watch
- Whether Cerebral markets Inflow as a treatment. Intended use is read from marketing, and Cerebral already uses that word.
- A trial with an active control, the stated limit of the 2026 result.
- Whether the billing complaints follow the app into Cerebral, which paid $5 million in FTC ordered refunds in 2025 over its own cancellation practices.
- Get Inflow Ltd’s next accounts, the only routine public window on the operating business.
- Any Inflow study appearing in a public trial registry.
In their words
“Inflow can offer immediate, affordable, and on-demand support in ways our burdened mental health system simply cannot. There’s no waitlist, no need for a referral, no complicated intake process.”
Seb Isaacs, co-founder, TechCrunch, 2022 · Independent
“We’re building a holistic approach for people with ADHD that encompasses all aspects of their care journey, and we are the only company doing this”
Seb Isaacs, co-founder, TechCrunch, 2023 · Independent
“People with ADHD represent around 10 per cent of the global population and Inflow is offering a new way to help them access the most effective support.”
Will Gibbs, partner, Octopus Ventures, BusinessCloud, 2023 · Investor
“I think that expectation of neurotypical behavior is hopefully changing in companies so that if somebody acts a little bit different, they are not judged as less than or atypical, it’s just different.”
Dr George Sachs, ADHD reWired podcast, 2021 · Interview
“There’s been a massive increase in awareness and a big increase in diagnosis, but there’s still that gap between people who are looking for support and actually getting formal care.”
Levi Epstein, CEO and co-founder, Behavioral Health Business, 2026 · Independent
Related companies
Sources
- Public recordForm D, Inflow Holdings, Inc., CIK 0001953738
- Public recordRecords for Get Inflow Ltd (12625083) and Inflow Holdings, Inc. (FC039076)
- Public recordUsability and feasibility of a cognitive-behavioral mobile app for ADHD in adults
- Public recordBridging the Gap: Digital CBT for Adults Managing ADHD Challenges
- Public recordDe Novo DEN200026, EndeavorRx
- Public recordSearches for Inflow, no registered studies
- IndependentInflow seed and Series A coverage, 2022 and 2023
- IndependentCerebral’s Latest Acquisition Marks Its Reentry into ADHD Care
- IndependentInflow ADHD App Review 2026
- Independentgetinflow.io customer reviews
- InterviewNeurodiversity and the Inflow App with George Sachs
- InvestorOur investment in Inflow
- IndependentFDA’s 2026 Guidance on General Wellness Devices
- CompanyCerebral Acquires Leading ADHD Behavioral App, Inflow
- CompanyInflow FAQ and App Store listing
Profile researched and written by Healthcare Discovery. Last updated September 29, 2026.
