Science

Methodology & Sources

How we decide what goes in the app — and how you can check it.

Quit Science is built on the published medical literature. Every recovery milestone and myth-bust is graded for how strong the evidence is and, wherever a specific claim is made, linked to the original study. This page explains the grading system, the principles behind it, and lists all 18 peer-reviewed sources in one place.

How we grade evidence

Every milestone carries one of three labels so you can weigh it appropriately. We'd rather tell you a claim is preliminary than dress it up as settled science.

Well-established

Supported by systematic reviews, meta-analyses, randomized trials, or large prospective cohorts. The direction and rough timing of the effect are settled in the literature.

Moderate evidence

Supported by smaller human studies, consistent observational data, or well-understood physiology — but exact timelines vary between people and some findings are still being replicated.

Preliminary

Based on early, limited, or mechanistic evidence. Plausible and directionally supported, but the magnitude and timing carry real uncertainty. Treated as informative, not definitive.

Our sourcing principles

Peer-reviewed first

Recovery claims are tied to published studies in the medical literature — journals like Nature Communications, NEJM, The Lancet, BMJ, PNAS, and JACC — not blogs, marketing copy, or anecdote.

Human studies prioritized

Where human data exists, we cite it over animal or in-vitro work. Mechanistic and animal findings are used only to explain the "why," and are flagged as lower-evidence.

Every claim is traceable

Milestones and myth-busts carry inline citations that link straight to the DOI, PubMed, or PMC record. Nothing here is meant to be taken on faith — you can read the primary source.

Ranges, not false precision

Recovery timing varies with how much and how long you drank, genetics, and overall health. We show typical windows and grade our confidence rather than promising exact dates.

Honest about uncertainty

When the evidence is mixed or early, we say so — and we bust over-optimistic myths (like "the liver fully regenerates in 30 days") rather than repeat them.

Reference library

The 18 peer-reviewed sources behind our milestone and myth content. Each links to the published record so you can read it yourself.

  1. 1.

    Bagnardi V, Rota M, Botteri E, et al. Alcohol consumption and site-specific cancer risk: a comprehensive dose-response meta-analysis. British Journal of Cancer. 2015;112(3):580-593.

    View sourceDOI: 10.1038/bjc.2014.579PMID: 25422909
  2. 2.

    Bishehsari F, Magno E, Swanson G, et al. Alcohol and Gut-Derived Inflammation. Alcohol Research: Current Reviews. 2017;38(2):163-171.

  3. 3.

    Daviet R, Aydogan G, Jagannathan K, et al. Associations between alcohol consumption and gray and white matter volumes in the UK Biobank. Nature Communications. 2022;13:1175.

    View sourceDOI: 10.1038/s41467-022-28735-5PMID: 35256565
  4. 4.

    Durazzo TC, Mon A, Gazdzinski S, et al. Serial longitudinal MRI data indicate non-linear regional gray matter volume recovery in abstinent alcohol-dependent individuals. Addiction Biology. 2015;20(5):956-967.

    View sourceDOI: 10.1111/adb.12180PMID: 25212755
  5. 5.

    Ebrahim IO, Shapiro CM, Williams AJ, Fenwick PB. Alcohol and sleep I: effects on normal sleep. Alcoholism: Clinical and Experimental Research. 2013;37(4):539-549.

    View sourceDOI: 10.1111/acer.12006PMID: 23347102
  6. 6.

    Estruch R, Coca A, Rodicio JL. Effect of Alcohol Abstinence on Blood Pressure: Assessment by 24-Hour Ambulatory Blood Pressure Monitoring. Hypertension. 1999;33(2):653-657.

    View sourceDOI: 10.1161/01.HYP.33.2.653
  7. 7.

    Funayama T, Tamura Y, Takeno K, et al. Effects of alcohol abstinence on glucose metabolism in Japanese men with elevated fasting glucose: A pilot study. Scientific Reports. 2017;7:40277.

    View sourceDOI: 10.1038/srep40277PMID: 28067302
  8. 8.

    Gapstur SM, Bouvard V, Nethan ST, et al. The IARC Perspective on Alcohol Reduction or Cessation and Cancer Risk. New England Journal of Medicine. 2023;389(26):2486-2494.

    View sourceDOI: 10.1056/NEJMsr2306723PMID: 38157507
  9. 9.

    GBD 2016 Alcohol Collaborators. Alcohol use and burden for 195 countries and territories, 1990-2016: a systematic analysis for the Global Burden of Disease Study 2016. Lancet. 2018;392(10152):1015-1035.

    View sourceDOI: 10.1016/S0140-6736(18)31310-2PMID: 30146330
  10. 10.

    Gunn C, Mackus M, Griffin C, et al. A systematic review of the next-day effects of heavy alcohol consumption on cognitive performance. Addiction. 2018;113(12):2182-2193.

    View sourceDOI: 10.1111/add.14404PMID: 30144191
  11. 11.

    Leclercq S, Matamoros S, Cani PD, et al. Intestinal permeability, gut-bacterial dysbiosis, and behavioral markers of alcohol-dependence severity. Proceedings of the National Academy of Sciences. 2014;111(42):E4485-E4493.

    View sourceDOI: 10.1073/pnas.1415174111PMID: 25288760
  12. 12.

    Manning V, Garfield JBB, Reynolds J, et al. Recovery of neuropsychological function following abstinence from alcohol in adults diagnosed with an alcohol use disorder: Systematic review of longitudinal studies. PLoS One. 2024;19(1):e0296043.

    View sourceDOI: 10.1371/journal.pone.0296043PMID: 38166127
  13. 13.

    Roerecke M, Kaczorowski J, Tobe SW, et al. The effect of a reduction in alcohol consumption on blood pressure: a systematic review and meta-analysis. Lancet Public Health. 2017;2(2):e108-e120.

    View sourceDOI: 10.1016/S2468-2667(17)30003-8PMID: 29253389
  14. 14.

    Schuckit MA. Recognition and Management of Withdrawal Delirium (Delirium Tremens). New England Journal of Medicine. 2014;371(22):2109-2113.

    View sourceDOI: 10.1056/NEJMra1407298PMID: 25427113
  15. 15.

    Stickel F, Datz C, Hampe J, Bataller R. Pathophysiology and Management of Alcoholic Liver Disease: Update 2016. Gut and Liver. 2017;11(2):173-188.

    View sourceDOI: 10.5009/gnl16477PMID: 28274107
  16. 16.

    Suzuki T, et al. Blood Pressure After Changes in Light-to-Moderate Alcohol Consumption in Women and Men: Longitudinal Japanese Annual Checkup Analysis. Journal of the American College of Cardiology. 2025.

    View sourceDOI: 10.1016/j.jacc.2025.09.018PMID: 41123524
  17. 17.

    Topiwala A, Allan CL, Valkanova V, et al. Moderate alcohol consumption as risk factor for adverse brain outcomes and cognitive decline: longitudinal cohort study. BMJ. 2017;357:j2353.

    View sourceDOI: 10.1136/bmj.j2353PMID: 28588063
  18. 18.

    Voskoboinik A, Kalman JM, De Silva A, et al. Alcohol Abstinence in Drinkers with Atrial Fibrillation. New England Journal of Medicine. 2020;382(1):20-28.

    View sourceDOI: 10.1056/NEJMoa1817591PMID: 31893513

Educational, not medical advice

This content is for education and motivation — it is not a diagnosis or a treatment plan, and it can't account for your individual health. Alcohol withdrawal can be medically dangerous for dependent drinkers; seizures and delirium tremens are real risks. If you drink heavily or daily, talk to a doctor before stopping. Always seek the advice of a qualified health professional with any questions about a medical condition.