Frequently Asked Questions
What makes Kiehl’s Powerful-Strength Line-Reducing Concentrate unique?
Our formula is clinically demonstrated to help reduce the appearance of lines and deep-set wrinkles, while boosting radiance and helping even skin texture over time. Formulated with antioxidant Pure Vitamin C, which is a powerful skincare ingredient that begins working immediately, our Vitamin C serum is potent, yet gentle enough for sensitive skin and formulated to enhance the efficacy of Vitamin C benefits with continued use. Our formula is specially designed to stabilize Vitamin C. It’s true, Pure Vitamin C can degrade when exposed to water, but our water-free formula helps to keep the high concentrations of Pure Vitamin C stable and effective.
What are the benefits of Vitamin C?
From boosting radiance to helping diminish the signs of aging to antioxidant protection, Vitamin C is a highly efficacious skincare ingredient with a wide range of benefits. It’s a popular ingredient with proven results and lots of science and research to back up its benefits for your skin. One of the best ways to incorporate this tried-and-true ingredient is in a Vitamin C serum, like our Powerful-Strength Vitamin C Serum. These concentrated complexion boosters provide a targeted treatment to help your skin look brighter, smoother, and healthier.
What are the different forms of Vitamin C within Powerful-Strength Line-Reducing Concentrate?
There are actually several different forms of Vitamin C that are used in skincare formulas. Vitamin Cg, or Ascorbyl Glucoside, is a potent derivative of Vitamin C that provides antioxidant protection and helps to minimize the visible signs of aging. Our Vitamin C serum is formulated with 2% Vitamin Cg to help enhance the efficacy of Vitamin C benefits over time. While they have overlapping benefits, Pure Vitamin C (L-Ascorbic Acid) is absorbed into skin and starts working immediately upon contact while Vitamin Cg (Ascorbyl Glucoside) activates once absorbed into the upper layers of skin to boost Vitamin C activity over time. Kiehl’s Vitamin C serums and formulas effectively incorporate a form of topical Vitamin C that is carefully selected to maximize its targeted efficacy.
Should you pair Powerful-Strength Line-Reducing Concentrate with SPF?
We always recommend using SPF protection to help keep skin protected from UVA/UVB rays and pollution, which can cause the first signs of aging. The antioxidant benefits of Vitamin C can complement the protective effects of SPF. In fact, it is beneficial to apply Vitamin C before you head outdoors. Topical Vitamin C has been demonstrated to decrease generation of UVA-induced free radicals and can bolster skin’s antioxidant defenses with Vitamin E regeneration.
What age is a Vitamin C serum recommended for?
Our Vitamin C formula is designed for all ages and helps to visibly treat fine lines and wrinkles, uneven skin texture and the appearance of pores. Vitamin C levels deplete in skin over time, so using skincare products with Vitamin C is important as you grow older. However, our formula is still effective to use before you start to see fine lines and wrinkles. Our Vitamin C serum helps boost radiance and provide antioxidant protection to help defend skin from early signs of aging.
Is a Vitamin C serum recommended for sensitive and acne-prone skin?
Our vitamin C serums are carefully formulated and tested to be gentle enough for sensitive skin. Kiehl’s Powerful-Strength Line-Reducing Concentrate is formulated with Fragmented Hyaluronic Acid to help reduce the appearance of deep wrinkles and even skin texture for all skin types, including sensitive skin. When first starting with a Vitamin C serum, we recommend using once a day and building gradually to twice daily usage. If you have specific concerns, however, consult your dermatologist before incorporating new skincare products into your routine.
Does Powerful-Strength Line-Reducing Concentrate help with hyperpigmentation?
While this potent form of Vitamin C penetrates the skin’s surface layers to help visibly even skin tone and enhance clarity, we recommend our Clearly Corrective Dark Spot Solution for a targeted approach to treating hyperpigmentation and dark spots.
How do you apply your Vitamin C serum?
After you cleanse and tone your skin, apply 1-2 pumps of our Vitamin C serum. Smooth it on morning and night before your moisturizer to help lock in the skin benefits of your Vitamin C serum. While Vitamin C help defends skin during the day, it is also an effective ingredient to use in your nighttime skincare routine. For best results, use your Vitamin C serum twice a day, morning and night.
How often should you apply a Vitamin C serum?
As with products formulated with active ingredients, when first beginning to use a Vitamin C serum, start with a once-daily application, and gradually build to twice a day. With regular recommended usage in the morning and at night, our 50ml formula should last approximately 1 month. Always consult with your dermatologist when incorporating new skincare products into your routine.
Where do you store your Vitamin C serum?
Because L-Ascorbic Acid serums can degrade in heat and humidity, putting yours in the medicine cabinet could cause it to lose its effectiveness. While many L-Ascorbic Acid serums come in dark-colored or amber bottles that can help protect the formula from light, you should still be sure to keep your products away from direct sunlight.
Is it safe to use this product during pregnancy and breastfeeding?
While every ingredient we use in our products is evaluated for safety, we do not specifically test our products on women who are pregnant or nursing. Kiehl’s ensures there is substantial information supporting the safety of our products when used as directed by consumers. However, as there could be certain ingredients that physicians may not recommend for use during pregnancy and nursing, we always recommend that you discuss this with your physician and follow their advice.