Adenosine

What it is

Adenosine is one of the building blocks of DNA and of ATP, the molecule cells use to carry energy. Applied to skin it acts as a signalling molecule at cell-surface adenosine receptors, which influences fibroblast activity and local blood flow. It is used at very low concentrations - below the point where ingredient order stops indicating quantity on all twenty-seven masks here that carry it - and is popular in Korean and Japanese formulations because it is stable, odourless and works at a skin-friendly pH.

What it does well

• Softens the appearance of fine lines around the eyes and mouth

  Small controlled studies of adenosine-containing films and patches report measurable reductions in wrinkle depth over four to eight weeks. Effects are modest and cosmetic rather than structural.

  Moderate evidence

• Well tolerated even on reactive skin

  Adenosine is an endogenous human molecule used at very low levels, and irritation reports in the cosmetic literature are rare. It is often included in products aimed at sensitive skin for this reason.

  Moderate evidence

Worth knowing

• Most published evidence comes from combination products

  Adenosine is usually tested inside a formula that also contains hyaluronic acid, peptides or occlusive agents, so it is hard to separate its contribution from the rest. Independent single-ingredient trials are scarce.

  Matters most toAnyone choosing a product mainly because adenosine is on the label.

• Transient flushing is theoretically possible

  Adenosine causes blood vessels to widen, and some users report brief warmth or pinkness. At the very low levels used in cosmetics this is uncommon and short-lived.

  Matters most toPeople with rosacea or easily flushed skin.

Where the EU stands

Sources (2)

Every link goes to the original: a journal, a PubMed record or an EU document.

1. [1]
   Formulation, characterization, and efficacy of an adenosine-containing dissolvable film for a localized anti-wrinkle effect

   Journal of Cosmetic Science · 2007

   A randomised study of an adenosine-containing dissolvable film reported a measurable localised reduction in wrinkle appearance compared with control.

2. [2]
   Two-phase delivery using a horse oil and adenosine-loaded dissolving microneedle patch for skin barrier restoration, moisturization, and wrinkle improvement

   Journal of Cosmetic Dermatology · 2019 · doi:10.1111/jocd.12768

   An adenosine-loaded patch improved hydration and wrinkle measurements, though because the vehicle also delivered occlusive lipids the adenosine contribution cannot be isolated.