This little MAC Prep + Prime gem is designed to reduce the look of puffy eyes and under-eye shadows whilst priming the under eye area. I use a normal primer all over my face, avoiding the eye area and then apply this solely under/around the eyes, one pump is more than enough for both eyes. I let the product settle for a minute or so, as I think it helps give a better finished look. This primer is scentless & a very pale pink in colour.
I have tested this primer out with a liquid concealer and then with more creamy concealers and I would say this only really gives good results with a thinner, liquid concealer (I have been using Collection 2000's Illuminating Touch Concealer). When applying this concealer on top of this primer I can feel that there is actually a base product there, and there is some drag when applying and overall the primer creates a good base and helps reduce creasing and separating of my concealer. Honestly, I think with a thicker concealer, this product does not work well and I can never see amazing results.
With regard to puffy eyes, I do not actually suffer from this problem, so cannot comment. In contrast, I do suffer from under-eye shadows, so can tell you that this does help reduce those darker under eye areas, not by masking, but by generally brightening. This product gives purely cosmetic effects, and doesn't help tackle these problems over time.
This product has lasted me months, and therefore I could justify a repurchase at the price of £22.00 because it goes such a long way, although, I will not be rushing out to buy this again as it wasn't necessarily a miracle worker!
Do you have a favourite Prep + Prime product?