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The evidence

We cite our sources. All of them.

No vibes, no influencer hearsay. Every recommendation across our four pillars rests on peer-reviewed research — 14 primary sources, gathered here so you can check our work.

Tretinoin

The one ingredient with 40 years of proof.

Read the Tretinoin guide →
  1. Kligman AM, Grove GL, Hirose R, Leyden JJ. “Topical tretinoin for photoaged skin.”

    1986

    J Am Acad Dermatol

    Find it on PubMed →
  2. Fisher GJ, Kang S, Varani J, et al.. “Pathophysiology of premature skin aging induced by ultraviolet light.”

    1997

    N Engl J Med

    Find it on PubMed →
  3. Mukherjee S, Date A, Patravale V, et al.. “Retinoids in the treatment of skin aging: an overview of clinical efficacy and safety.”

    2006

    Clin Interv Aging

    Find it on PubMed →
  4. Kligman AM. “Topical tretinoin efficacy when combined with occlusion.”

    2005

    Dermatol Ther

    Find it on PubMed →
  5. Sahni V. “Tolerability of tretinoin in combined regimens.”

    2017

    J Drugs Dermatol

    Find it on PubMed →

Sunscreen

The cheapest anti-aging move you can make.

Read the Sunscreen guide →
  1. Hughes MCB, Williams GM, Baker P, Green AC. “Sunscreen and prevention of skin aging: a randomized trial.”

    2013

    Ann Intern Med

    The landmark Nambour trial — 900 subjects, daily SPF vs. discretionary use over 4.5 years. Daily users showed 24% less photoaging.

    Find it on PubMed →
  2. Flament F, Bazin R, Laquieze S, et al.. “Effect of the sun on visible clinical signs of aging in Caucasian skin.”

    2013

    Clin Cosmet Investig Dermatol

    Attributes up to ~80% of visible facial aging to UV exposure.

    Find it on PubMed →

Red Light

Lasers for your face, but make it at home.

Read the Red Light guide →
  1. Wunsch A, Matuschka K. “A controlled trial to determine the efficacy of red and near-infrared light treatment in patient satisfaction, reduction of fine lines, wrinkles, skin roughness, and intradermal collagen density increase.”

    2014

    Photomed Laser Surg

    Meta-analysis of 136 subjects — significant gains in collagen density and complexion after 30 sessions. The basis for FDA-cleared devices like Omnilux and CurrentBody.

    Find it on PubMed →
  2. Avci P, Gupta A, Sadasivam M, et al.. “Low-level laser (light) therapy (LLLT) in skin: stimulating, healing, restoring.”

    2013

    Semin Cutan Med Surg

    Find it on PubMed →

Quit Nicotine

What happens to your skin after that last Zyn.

Read the Quit Nicotine guide →
  1. Morita A. “Tobacco smoke causes premature skin aging.”

    2007

    J Dermatol Sci

    Find it on PubMed →
  2. Yin L, Morita A, Tsuji T. “Skin aging induced by ultraviolet exposure and tobacco smoking: evidence from epidemiological and molecular studies.”

    2001

    Int J Dermatol

    Find it on PubMed →
  3. Metelitsa AI, Lauzon GJ. “Tobacco and the skin.”

    2010

    Clin Dermatol

    Find it on PubMed →
  4. Ortiz A, Grando SA. “Smoking and the skin.”

    2012

    Int J Dermatol

    Find it on PubMed →
  5. Tsai KC, et al.. “Electronic cigarette use and premature skin aging.”

    2020

    J Am Acad Dermatol

    Find it on PubMed →

Citations point to the primary literature behind our guides. “Find it on PubMed” opens a search for the paper on the U.S. National Library of Medicine — the same database clinicians use. Spot something out of date or want a source we missed? Tell us.

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