Which serum should you use for dull skin?

What can vitamin C do for dull skin?

Vitamin C can reduce the appearance of dark spots and improve uneven skin tone. Research on skin damaged by the sun also found smoother skin and fewer wrinkles. These are useful changes if dullness means uneven colour or rough texture rather than simply wanting more moisture. Vitamin C is an antioxidant: it helps counter unstable molecules called free radicals that damage skin. Sunlight and air pollution generate these molecules. Vitamin C also supports collagen, the protein that helps give skin its structure.123

For dryness alone, vitamin C is not the obvious first choice. In trials comparing vitamin C with a placebo, hydration improved equally on both treated areas. Choose vitamin C for its effects on tone and texture, rather than treating it as a substitute for moisturizer.1

What should you look for on the bottle?

• Look for ascorbic acid or L ascorbic acid in the ingredients. These are names for vitamin C.
• Choose a concentration of 10% to 20%. Sensitive skin calls for the lower end; concentrations above 20% increase the risk of irritation.
• For L ascorbic acid, a pH below 3.5 is a studied formulation detail. Look for the strength and pH in the manufacturer's product information.
• Choose dark or tinted packaging rather than a clear bottle. Vitamin C is sensitive to sunlight, heat and light.

Dark packaging protects a light sensitive ingredient, even if it denies the serum its moment in the bathroom display. Vitamin C also comes in creams and lotions, so the dropper does not have exclusive rights to the ingredient.3

The ideal vitamin C concentration is not settled. A 23.8% L ascorbic acid formula improved uneven pigmentation, roughness and fine lines in 20 women with sun damaged skin after two weeks. That treatment combined a penetration enhancer with iontophoresis, a device assisted application method. For a home routine, use the 10% to 20% starting range rather than choosing the largest percentage.14

Test the serum before using it on your face

1. 1Choose a spot about the size of a quarter on the underside of your arm or inside your elbow.
2. 2Apply the normal amount twice daily for seven to 10 days. Leave the serum on as you would during normal use.
3. 3If the area stays free of redness, itching and swelling, begin using the serum on your face.
4. 4If a reaction develops, gently wash the serum off and do not use it again.

How do you apply vitamin C serum?

1. 1Wash with a gentle cleanser.
2. 2Apply a few drops of vitamin C serum to your face and neck.
3. 3Apply moisturizer.
4. 4Finish with broad spectrum sunscreen.

Begin every other day, then increase to daily use if your skin tolerates it. Morning application pairs vitamin C with sunscreen, though vitamin C can also be used at night. Vitamin C does not replace sunscreen or protective clothing.23

How long does brightening take?

Expect gradual improvement over about three months of consistent use. Take a photograph without makeup before starting, then another once a month to compare changes. Monthly photographs make the comparison easier than asking the bathroom mirror to maintain records. Longer use can be necessary for visible changes in pigmentation and sun damaged skin. Dark spot improvements can fade after you stop applying vitamin C.13

Who should be careful?

Sensitive skin needs a lower concentration and a gradual start. Read the full ingredient list, especially if you have a known sensitivity or allergy. Vitamin C skincare has been studied in adults and is not recommended for children. Mild tingling can occur, but substantial discomfort or irritation means stop using the serum and speak with a doctor. Dryness, itching and redness are possible side effects.23

For a skin reaction, a cool compress or petroleum jelly can help relieve symptoms after washing the product off. See a dermatologist if the reaction is severe and these measures do not help. If you cannot identify the ingredient causing repeated reactions, a dermatologist can arrange medical patch testing to investigate the cause.5