One of the most important things to consider when choosing a vitamin C brightening serum is the ingredients. Here is a summary of the ingredients and product details for several vitamin C brightening serums:

1. Skin&Lab Vitamin C Brightening Serum: This serum contains water, methylpropanediol, propanediol, glycerin, 1,2-hexanediol, niacinamide, and other ingredients.

2. Advanced Clinicals Vitamin C Brightening Serum: This serum contains aqua/water/eau, PEG-12 dimethicone, aminopropyl ascorbyl phosphate, ferulic acid, lactic acid, glycolic acid, and other ingredients.

3. Ursa Major Brighten Up Vitamin C Serum: This serum contains ascorbic acid polypeptide, a stable form of vitamin C, along with other natural actives that brighten dull-looking skin and lighten stubborn dark spots.

4. SKIN&LAB Vitamin C Brightening Serum: This serum contains hyaluronic acid, niacinamide, and other vitamins in addition to vitamin C.

5. Urban Skin Rx Super C Brightening Serum: This serum contains vitamin C, arbutin, kojic acid, hyaluronic acid, salicylic acid, and other ingredients.

6. Jubel Naturals Vitamin C+ Brightening Serum: This serum contains vitamin C, plant stem cells, hyaluronic acid, and other ingredients.

Positive and negative aspects of these products were not mentioned in the search results.