Al
Alpha Lipoic Acid
Thioctic Acid · Alpha Lipoic AcidAntioxidant
Sulfur-bearing antioxidant. Both water- and oil-soluble; supportive role in serum formulations.
What it does
Alpha lipoic acid is unusual among antioxidants in being soluble in both water and oils, which lets it operate in both environments at once. Topical effects on photoaging and texture have been reported in small studies but the overall topical evidence base is moderate. As with many antioxidants, the pairing matters — ALA is most useful as a supporting ingredient in a vitamin C / vitamin E / ferulic acid stack.
The evidence, graded
strongVitamin C, vitamin E, and ferulic acid show synergistic photoprotection. The combination is more stable and doubles photoprotection compared to vitamin C alone.Lin 2005 · Journal of Investigative Dermatology ↗
strongAntioxidants neutralize free radicals generated by the UV that gets through sunscreen. Layering an antioxidant serum under SPF compounds photoprotection.Wu 2011 · Clinical and Experimental Dermatology ↗
Graded per the methodology: strong · moderate · emerging · expert consensus. A weak source on a strong claim gets the weaker label.
Also known as
ala, thioctic acid
Pairs worth knowing
This page is public and indexed on purpose (unlike profiles and drops, which are unlisted) — it’s the citation behind shared ingredient cards, and it should be findable.
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