Serum vitamin c 21.5 review năm 2024

The By Wishtrend Pure Vitamin C 21.5% Advanced Serum is an effective and cosmetically elegant formula that contains only 10 ingredients, which is composed of 70% Sea-buckthorn (vitamin tree) water and 21.5% ascorbic acid, which has been shown to help treat pigmentation, protect from UV damage, assist wound healing and improve collagen formation.

Claims:

This high concentration vitamin ampoule is made with Vitamin Tree Water and pure Vitamin c to deliver the concentrated effects of vitamin c to the skin. The serum removes dead skin cells to even out the skin tone and brightens the complexion.

To read more about the Wishtrend, and the other products I have tried and recommend, click here.

Appearance and Scent:

The constancy is similar to that of water, which makes it easily absorbed into the skin. It feels very lightweight and absorbs without any residual stickiness. The fragrance-free formula has no discernible scent.

Packaging, Size and Expiry:

The serum comes in a dark brown glass bottle with an eyedrop applicator. It is packaged with a sealed screw cap with a plastic security seal. The dropper comes separately in a sealed bag plastic bag. This minimises the risk of accidental spillage during shipping and helps prevent oxidation of the ingredients. The bottle contains 30 mls of product and expires six months after opening, and two years after manufacture. This size bottle lasted me for approximately six months. Wishtrend advises this product to be kept refrigerated once opened to extend the stability of the formula.

Cost and Number of Uses:

The Pure Vitamin C Advanced Serum retails for NZD $47.70 or US $30.00. The serum lasted me around three to four months with daily use.

How to Use:

After cleansing and toning, dispense a few drops of the serum and gently pat into the skin. Follow with the rest of your skincare routine and always use sunscreen during the day. Use in the morning or evening. Avoid using products that contain hydroxy acids or retinol at the same time as Vitamin c containing products.

Formulation Science:

Healthy skin naturally contains a high concentration of vitamin c when compared to other body tissues, and skin has a higher concentration than that of plasma, suggesting it actively accumulates in the skin after transportation to the cells from blood cells. Several studies have shown that vitamin c levels are lower in aged individuals or those with photodamaged skin. If the plasma concentration of vitamin c is low, it can be applied topically to the epidermal layer of the skin, however, the effectiveness of this depends largely on the formulation of the vitamin c containing product. As vitamin c is a water-soluble and a charged molecule, it is repelled by the physical barrier of epidermal cells. Only when the pH level is below 4, and if the vitamin c is present as ascorbic acid then some penetration into the epidermis can occur.

Ascorbic acid is highly sensitive to air and light and as such is very difficult to prevent oxidation in cosmetic preparations. Studies performed on pigs have suggested that formulations with a pH below 3.5 will result in greater penetration of the ascorbic acid into the skin. Vitamin c is also very unstable when mixed with water and can oxidize into the dark yellow coloured dehydroascorbic acid.

This product was formulated with a low pH (I got a result of 2.9 when I tested my bottle), combined with the addition of ascorbic acid as an ingredient and the light-proof packaging, makes this an excellently formulated product that is likely to be very effective in reducing pigmentation and improving the overall skin tone.

This serum is a more concentrated version of the newly released By Wishtrend Pure Vitamin C 15% with Ferulic Acid. You can read my review of that serum here.

Ingredients:

Hippophae rhamnoides water, ascorbic acid, sodium lactate, 1,2-hexanediol, sodium hyaluronate, panthenol, cassia obtusifolia seed extract, allantoin, xanthan gum, ethyl hexanediol

Ingredient Analysis:

Hippophae rhamnoides water also known as Sea-buckthorn, is extracted from the fruit and seeds of the Hippophae rhamniodes plant. The plant possesses a number of active ingredients that are commonly used in many cosmetic products to give skin a healthy appearance. It is especially useful in treating dry, flaky or ageing skin due to its unique unsaturated fatty acid composition, which includes, palmitoleic acid (omega-7) and gamma-linolenic acid (omega-6). It is able to easily pass through the epidermis, softening skin and improving elasticity. The gamma-linoleic acid is converted to prostaglandins, offering protection against infection, allergies and inflammation resulting in anti-ageing and improving the appearance of scars and enhancing wound healing.

This study published in the International Journal of pharmacological science looked at the changes in skin barrier function following long-term application of 5% sea-buckthorn oil and water in water emulsion. The 13 subjects applied either the emotion or a placebo for 12 weeks. The emulsion containing the sea buckthorn resulted in significant improvements in skin hydration and transepidermal water loss (TEWL), and a significant improvement in the skin barrier function was observed.

Ascorbic acid, also known as Vitamin C, is the most abundant antioxidant in the skin. It is an essential water-soluble micronutrient that plays in a central role as a cofactor and several enzymatic reactions and cellular processes including collagen synthesis, cellular oxidation, and is instrumental in the protection of cells against oxidative damage caused by free radicals and reactive oxygen species (ROS) that accumulate and cause disease like cancer, and ageing associated with oxidative stress. Vitamin C has been shown to be effective at wound healing, and this is directly related to its ability to act as a cofactor for the synthesis of new collagen.

Sodium lactate is the sodium salt of lactic acid, a component of the natural moisturisation factor (NMF) and plays a role in maintaining the hydration of the skin. It is produced by the fermentation of sugar and plays a role in maintaining the hydration of the skin.

Hyaluronic acid and its derivatives offer superior moisturization as the skin-identical molecules are capable of penetrating deep into the dermis and absorbing 1000 times their weight in water. The lower the molecular weight, the deeper the molecule can penetrate the skin. Sodium Hyaluronate is the salt form of hyaluronic acid that exists as a smaller molecular size than hyaluronic acid, is more water-soluble, and is less likely to oxidize. It provides more significant moisturization as the molecule is capable of penetrating deeper into the dermis. It is ideal for use in skincare due to its biocompatibility, consistency, and hydrophilicity (water-loving nature).

Panthenol is the provitamin of B5 and functions as a moisturizer and emollient. It is especially useful for calming irritation, relieving itching, healing wounds and treating sunburn.

Cassia Obtusifolia extract is a plant seed extract high in polysaccharides that act as skin conditioning agents. The extract is anti-inflammatory and assists in the healing of acne and capable of mimicking the water plumping the effect of hyaluronic acid.

Allantoin is a healing and anti-inflammatory ingredient derived from urea that exhibits keratolytic action (removes excess keratinized epithelial cells) and stimulates cell division and replication of epithelial cells. This accelerates the regeneration of damaged skin and allows the skin to retain moisture and rebuild the protective moisture barrier. It acts as a moisturizing agent and is commonly found in skincare formulated for dry skin, acne, or allergies.

pH Testing:

I got a pH result of 2.9.

pH Analysis:

The pH of this serum is below the pH of the skin (range 4.0-6.0, average 4.7). However, this is due to the ascorbic acid (Vitamin c) requiring an acidic pH to work optimally (between pH 2.0-3.5). Learn why the pH of skincare products is so important here. This particular serum will also have some mild exfoliating properties.

My Experience:

Since I have been using the serum, I have noticed a decrease in my melasma, And my overall skin texture and brightness has improved. I have fewer issues with post-inflammatory erythema (the redness that can occur after a blemish), and my skin has a nice even tone and glow.

Overall Impressions:

This serum is a thin watery consistency that applies without a sticky residue and sinks completely into the skin. It is advised to let it absorb for 15 minutes for continuing with other products and to start using this product gradually if your skin is not used to this concentration of vitamin c. Generally vitamin c serums would ideally be used in the morning (before sunscreen) to get the benefits of additional antioxidant protection, however, as this is a highly concentrated serum I would consider it as an intense treatment rather than a daily serum. Because of this, I prefer to use it at night alternating with other active ingredients. Anyone not using retinoids may tolerate the formula more frequently but I have noticed benefits from using it every other night. This is a great serum for the more advanced vitamin c user. If you are new to vitamin c this concentration, I suggest you start with the By Wishtrend Pure Vitamin C 15% with Ferulic Acid serum, available here.

Things I Liked:

  • Formulated at the correct pH
  • A simple formulation containing only 10 ingredients
  • Free of perfumes, alcohol, and essential oils
  • Affordable
  • Packaging protects the formulation from light
  • Cruelty-free and vegan

Things I Disliked:

  • The dropper bottle does not protect the product from the air
  • The glass packaging is not travel friendly
  • The shelflife is relatively short and requires refrigeration

Where to Purchase:

By Wishtrend products are available at Wishrtend, and Amazon

Please note these are affiliate links, and they help my blog to grow. No extra cost is passed on to you, and your support is greatly appreciated.

How effective is 20% vitamin C serum?

20% Stabilised Vitamin C Solution It brightens skin, visibly reduces the appearance of dark spots, supports your skin's natural collagen production, reduces the appearance of wrinkles and helps protect your skin against environmental damage.

What percent of vitamin C serum is best?

Concentration: The sweet spot for the concentration level is between 10 and 20 percent. You definitely want a concentration that's higher than 8 percent for maximum effectiveness. But going over 20 percent could lead to irritation and doesn't increase its benefit.

How long does it take for 20% vitamin C serum to work?

How Soon Will I See Results? You may see results from as little time as 2 weeks to 4 months. These results could be brighter more luminous skin, less hyperpigmentation and more hydrated skin, or a decrease in wrinkles and fine lines (or both).

Does vitamin C serum actually work?

“There's good scientific evidence to show that vitamin C has antioxidant effects,” Dr. Piliang says. “Using topical vitamin C can result in less cell damage and better-looking skin.”

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