About 66 days, not 21
University College London. In a study of everyday habit formation, a new behaviour took a median of about 66 days to become automatic, with individual times ranging from 18 to 254 days. The popular "21 days" figure is not what the research found.
Where Vow uses it: Everyone — it is why Vow marks day 66 as a milestone.
Reference: Lally, P., van Jaarsveld, C. H. M., Potts, H. W. W., & Wardle, J. (2010). How are habits formed: Modelling habit formation in the real world. European Journal of Social Psychology, 40(6), 998–1009. DOI 10.1002/ejsp.674
Cravings rise, peak and pass
University of Washington. Urge surfing — observing a craving as it rises, peaks and falls instead of fighting or obeying it — was developed by G. Alan Marlatt and colleagues at the Addictive Behaviors Research Center and forms part of Mindfulness-Based Relapse Prevention.
Where Vow uses it: The Craving Shield, which paces you through the wave.
Reference: Bowen, S., Chawla, N., Collins, S. E., et al. (2009). Mindfulness-Based Relapse Prevention for Substance Use Disorders: A Pilot Efficacy Trial. Substance Abuse, 30(4), 295–305. DOI 10.1080/08897070903250084
Recovery starts within minutes
World Health Organization · U.S. Surgeon General. After the last cigarette, heart rate and blood pressure drop within 20 minutes and the carbon monoxide level in the blood returns to normal within 12 hours; within a year, the added risk of coronary heart disease is about half that of a smoker.
Where Vow uses it: The recovery timeline for smoking.
Reference: World Health Organization, Tobacco: health benefits of smoking cessation; U.S. Department of Health and Human Services, Smoking Cessation: A Report of the Surgeon General (2020). WHO — Health benefits of smoking cessation · Surgeon General’s report (2020)
Behaviours use the same reward system
NIDA · American Psychiatric Association. Addiction research from the U.S. National Institute on Drug Abuse describes how repeated rewards reshape the brain’s dopamine-driven reward circuitry, and the American Psychiatric Association classifies gambling disorder alongside substance use disorders in DSM-5.
Where Vow uses it: Behavioural habits such as gambling and porn.
Reference: Volkow, N. D., & Morales, M. (2015). The Brain on Drugs: From Reward to Addiction. Cell, 162(4), 712–725. American Psychiatric Association, DSM-5 (2013). DOI 10.1016/j.cell.2015.07.046 · APA — What is gambling disorder?
How we write health content
Our 32 answers about quitting follow the same rules as the app:
- Every number, timeline or medical statement has a source — the World Health Organization, a national health service such as the NHS, a U.S. health agency such as the CDC, NIH, NIDA, NIAAA, FDA or SAMHSA, a regulator, or peer-reviewed research.
- Sources are read, not remembered. Each source page is opened when the answer is written, and the passage supporting the claim is quoted on the page for you to check.
- No commercial or community sources — no treatment-centre marketing, blogs, forums or other apps.
- Uncertainty is stated. Where research is limited or contested — such as recovery timelines for compulsive porn use — the answer says so rather than filling the gap.
- Safety comes first. Any answer that touches alcohol or drug withdrawal says clearly when to see a doctor.
- Dated. Each answer shows when it was last reviewed.
Vow is not a medical service, and none of this is personal medical advice. See the medical disclaimer.
Corrections
If you find an error, an outdated figure or a broken source, email support@heyvow.com. We check it against the source and update the page and its review date.