I thought it would be interesting if I start this series where I compared similar products to help you choose the best one. Today’s I will compare the new La Roche Posay C10 serum with the one from Eucerin
La Roche Posay C10 serum retails for 32.20€ and the Eucerin for 34.81€.
The price points are fairly similar.
Both of them use the ascorbic acid form of vitamin C. The vitamin C that our body use is the L ascorbic acid. Some other derivatives are interesting but are likely not as useful as the natural form of vitamin C. I wish La Roche Posay and Eucerin would disclose if they use the L-ascorbic acid and not a mix between L and D form. D-ascorbic acid is useless for our cells.
La Roche Posay C10 formula
It is serum with glycerin, silicones and two forms of hyaluronic acid. According to the formula it has nice humectants. There is one peptide (acetyl dipeptide-1 cetyl ester) that soothes the skin. I would prefer that LRP has used other anti-inflammatory ingredient rather than one. I have lots of cons for this formula: it contains alcohol and perfume. Alcohol dries out the skin by removing some of the lipids in the skin barrier and hence helps the vitamin C to penetrates deeper and the perfume also (hi irritation). On their website, LRP claims that this serum has a physiological pH (pH 5). It has been demonstrated that L-ascorbic acid has to be formulated at pH3 to penetrates the skin barrier.
LRP claims that this serum is good for sensitive skin despite the perfume and alcohol. I doubt that you will benefit from the antioxidant properties of vitamin C in this serum.
Eucerin Vitamin C booster formula
This serum contains emollients and humectants. It has squalane a natural lipid found in our skin and few nice humectants glycerin and hyaluronic acid notably. It is nice that Eucerin has used licorice extract to soothe the skin. Like for LRP, I would have preferred more soothing ingredients. The pH is of 4 close to pH3 which is nice. The vitamin C is likely efficient in this formula. What I love the most is the genius packaging. Each vial has to be used once a week. You cracked the vitamin C into the liquid. L-ascorbic acid gets oxidize quickly upon air exposure with this packaging you are sure that your vitamin C is fresh.
Without any surprise the winner is Eucerin. This vitamin C booster is excellent if you want antioxidants with a brightening effect L ascorbic acid is a good choice. I wish Eucerin would have not added perfume. 10% of vitamin is on the lower side 15 to 20% is more efficient but harder to tolerate.
I have made a video about it.
Thank you for your time.