Ingredients List

Most common cosmetic ingredients

Thee are thousands of ingredients in your daily makeup or skincare products.While the formula of each product differs slightly, most cosmetics contain a combination of at least some of the following ingredients. This article cosmetic ingredients course, focuses on most popular cosmetic ingredients Find your favorite cosmetic & skincare ingredient, and read about it!

• Benzoyl peroxide 
• Salicylic acid
• Silicon 
• Paraben 
• Fragrance 
• Vitamin C
• Vitamin E
• Collagen 
• Hyaluronic Acid 
• Nano silvers 

A

• Allantoin

• Alcohol Denat
• Almond Oil
• Aloe Vera
• Alpha Hydroxy Acid
• Amala Oil
• Amino Acids
• Amoxicillin
• Antioxidants
• Apple Cider Vinegar
• Apricot Kernel Oil
• Arbutin
• Argan Oil
• Argireline
• Ascorbyl Glucoside
• Astaxanthin
• Avocado Oil
• Azelaic Acid
• Azulene

B

• Baobab
• Baking Soda
• Bakuchiol
• Bentonite Clay
• Benzyl Alcohol
• Beta Glucan
• Bhringraj Oil
• Biotin
• Bio Oil
• Black Cumin Seed Oil
• Borage Seed Oil
• Butylene Glycol

C

• CBD Oil
• CBD
• Caffeine
• Calamine Lotion
• Camellia Extract
• Capric Triglyceride
• Caprylyl Glycol
• Carbomer
• Caviar Extract
• Carrier Oils
• Castor Oil
• Cephalexin
• Ceramides
• Cetearyl Alcohol
• Chamomile
• Charcoal
• Chebula
• Chia Seed Oil
• Citric Acid
• Cocamidopropyl-Betaine
• Cocoa Butter
• Coconut Oil
• Collagen
• Colloidal Oatmeal
• Cone Snail Venom
• Copper Peptides
• CoQ10
• Cyclopentasiloxane
• Cypress Oil

D

• Desitin
• Dihydroxyacetone
• Dimethicone
• Doxycyclin

E

• Emolli
• ents
• Emu Oil
• Epsom Salt
• Eucalyptus Oil
• Evening Primrose Oil

F

• Ferulic Acid
• Fermented Oils
• Frangipani

G

• Gluconolactone
• Glycerin
• Glycolic Acid
• Goat’s Milk
• Goji Berry
• Gold
• Grapeseed Oil
• Green Tea

H

• Hemp Oil
• Homosalate
• Honey
• Humectants
• Hyaluronic Acid
• Hydrocortisone
• Hydrogen Peroxide
• Hydroquinone

I

• Isododecane
• Isoparaffin
• Isopropyl Myristate

J

• Jojoba

K

• Kaolin
• Karanja Oil
• Kigelia Africana
• Kojic Acid
• Kukui Nut Oil

L

• Lactic Acid
• Lactobionic Acid
• Lanolin
• Lavender Oil
• Lemon Juice
• Licorice Extract
• Lysine

M

• Madecassoside
• Magnesium
• Magnesium Aluminum Silicate
• Malic Acid
• Mandelic Acid
• Manuka Honey
• Marshmallow Root Extract
• Marula Oil
• Meadowfoam
• Methylparaben
• Mineral Oil
• Moringa Oil
• Murumuru Butter
• Muslin

N

• Neem Oil
• Niacinamide
• Nizoral

O

• Oat
• Octinoxate
• Octisalate
• Octocrylene
• Olive Oil
• Omega Fatty Acids
• Oxybenzone

P

• Panthenol
• Parabens
• Peppermint Oil
• Petroleum Jelly
• PHA
• Phenoxyethanol
• Phytic Acid
• Phytosphingosine
• Placenta
• Plum Oil
• Polyglutamic Acid
• Polypeptides
• Pomegranates
• Prickly Pear Oil
• Probiotics
• Progeline
• Propanediol
• Propolis
• Propylene Glycol
• Propylparaben
• Purslane Extract
• Pycnogenol

Q

• Quercetin

R

• Reishi Mushrooms
• Resveratrol
• Retin-A
• Retinaldehyde
• Retinol
• Retinyl Palmitate
• Rosehip Oil
• Rosemary
• Royal Jelly

S

• Safflower Oil
• Salicylic Acid
• Sea Buckthorn Oil
• Sea Salt
• Seaweed
• Sea Moss
• Shea Butter
• Silver
• Snail Mucin
• Sodium Ascorbyl Phosphate
• Sodium Deoxycholate
• Sodium Hyaluronate
• Sodium Hydroxide
• Sodium Lauroyl Lactylate
• Sodium Lauryl Sulfate
• Sodium Palmate
• Sodium PCA
• Sodium Tallowate
• Soybean Oil
• Spironolactone
• Stearic Acid
• Stearyl Alcohol
• Squalane
• Stem Cells
• Succinic Acid
• Sulfates
• Sulfur
• Sunflower Oil
• Synthetic Beeswax

T

• Talc
• Tamanu Oil
• Tea Tree Oil
• Tepezcohuite
• Tranexamic Acid
• Tretinoin
• Triethanolamine
• Turmeric

U

• Undecylenic Acid
• Urea 40

V

• Vegetable Glycerin
• Vitamin A
• Vitamin B3
• Vitamin C
• Vitamin D
• Vitamin E
• Vitamin F
• Vitamin K
• Volcanic Ash

W

• Willow Bark Extract

X

• Xanthan Gum

Z

• Zinc

Antioxidant

Antioxidants are compounds that play a significant role in cosmetics and skincare. They fight free radicals, slow the aging process, and so many other overall health benefits.

-What is an Antioxidant?

Antioxidants are compounds that inhibit Oxidation and stop damage-causing chain reactions. Oxidation is a chemical reaction that can produce free radicals and chain reactions.

-Does antioxidants penetrate through the skin?

Skin penetration depends on many factors, one of which is the type and size of the molecule. as a result, it depends on what kind of antioxidant we are dealing with. There are many types of antioxidants. Many studies show the ability of antioxidants to be absorbed into skin cells. However, skin penetration is very complicated. Regardless of penetration, antioxidants are still beneficial even without penetrating through the skin because most free radicals stay on the top layer of the skin.

-How do antioxidants protect the skin?

Antioxidants protect skin cells against the damaging effects of free radicals. Free radicals can cause oxidative stress in the skin, which will cause cancer, aging, inflammation, and photodamage.

Free Radicals

-What is free radical?

Free radicals are unstable molecules that damage skin cells.

-How do free radicals cause damage?

These molecules are missing an electron, so they want to steal it from stable molecules to balance themselves out.

-Free radical skin damage

If a free radical steals an electron from one of the proteins contained in a strand of collagen (rather than a loose protein), it causes a change in the chemical structure of the collagen, which causes a break in the collagen strand. This process is how free radicals can cause severe damage to the skin.

Benzyl Peroxide

–What is Benzoyl Peroxide?

Benzoyl Peroxide is the main ingredient of acne treatments. It kills acne-causing bacteria; no prescription is needed to purchase the product, including B.P.O.

–How does B.P. kill acne bacteria?

Once the skin absorbs B.P.O., it will turn into benzoic acid. Most benzoic acid releases active free-radical oxygen species. The p.acne bacteria can’t survive in a rich oxygen environment; the oxygen species oxidize the bacterial protein.

–Is B.P.O. safe for the skin?

B.P.O. can cause redness, irritation, and dryness to the skin. Killing the P.acne bacteria includes releasing free radicals on the skin and speeding up aging, but because of its effectiveness in treating acne, most acne products include Benzoyl Peroxide.

–B.P.O. percentage

Based on recent research, different percentage of B.P.O. in acne products have the same effect on acne. As a result, it is better to use a less percentage of B.P.O. (2-5%).

–How is benzoyl peroxide produced?

Production of B.P.O. happens in the lab through the reaction of benzoyl chloride, sodium hydroxide, and hydrogen peroxide.

–Other uses of B.P.O.

Hair-dying treatments, teeth-whitening, and bleaching agents also use B.P.O. as their main chemical. However, acne treatments are the most popular ones.

–What’s the difference between salicylic acid and B.P.O.?

Salicylic acid only targets a cause of acne, but B.P.O. kills the acne bacteria itself. Salicylic acid does not kill bacteria. Anyways, most acne treatments use both of these chemicals in combination.

Cannabis

Cannabis products and terms can be very confusing to understand the difference between c.sativa, hemp, Marijuana, T.H.C., CBD, and cannabis or cannabinoids. 

– Let’s Review All the Different Terms

C.sativa

C.sativa  is a plant from Central Asia, and there are three standard varieties of cannabis plants: C. indica, C. Sativa, and C. ruderalis. 

Cannabinoid:

Cannabinoid is a set of chemicals that exists in the cannabis plant. 

CBD chemical:

CBD is a type of cannabinoid chemical that does not get you high 

T.H.C. chemical:

T.H.C. is a type of cannabinoid chemical that gets you high

Marijuana: 

Marijuana is a specific species of c that has more T.H.C. We have two types of Marijuana which are called Sativa and Indica 

Hemp:

Hemp is a particular species of cannabis that has the less than 0.3%.

-What is Sativa or Indica ?

Sativa and Indica are different strains of the Cannabis plant, and their primary use is for medicinal and recreational purposes. 

-What is the difference between Sativa and Indica?

Sativa and Indica are both considered Marijuana because they both have more than 0.3 percent T.H.C.

Different Chemical

Sativa: Sativa strains are almost exclusively T.H.C. dominant and do not contain CBD.

Indica: Indica strains typically contain higher amounts of CBD than T.H.C.

Different High

Sativas: is known for their “head high,” a refreshing, energizing effect that can help reduce anxiety or stress, and increase creativity and focus. 

Indicas: are typically associated with full-body effects, such as increasing deep relaxation and reducing insomnia. 

Note: Cannabinoid products have many different benefits in cosmetics and skincare; many different cosmetic products use different forms of Cannabinoids as the main ingredient in their formulations. Read more

CBD

CBD in cosmetics is becoming very popular as researchers discover more and more benefits of CBD in skincare.

CBD Benefits for Skin 

Acne

Acne is the most common skin condition on human skin.

There is two significant way to treat acne:

1. reducing the sebum production 
2. Reducing infection 
3. Treating acne scars 

-How does CBD treat acne?

Sebocytes are the cells that create sebum, which is a waxy, oily substance the skin produces. Excessive sebum can also result in acne. A 2014 study by a trusted Source explored the effects of CBD on human sebocytes. The study indicates that CBD can prevent sebocytes from creating too much sebum. Also, another study proves CBD includes potential antibacterial and antifungal properties, which can help reduce p.acne bacteria. A 2019 study suggests that CBD may also be beneficial for treating the appearance of acne scars. 

Learn more 

Dryness and itching

A 2019 study notes CBD may be beneficial for reducing potential eczema, dermatitis, and psoriasis triggers.

Learn more about CBD and psoriasis here.

Aging and wrinkles

A 2017 study shows the antioxidant and anti-inflammatory properties of CBD. The antioxidant helps slow the aging process. 

 

CBD in Cosmetic 

-How do they use CBD in cosmetics?

Manufacturers use heat to extract CBD from the cannabis plant and mix it with carrier oil to produce CBD oil. Another way is to use alcohol to create a CBD tincture.

-How to use CBD oil?

You can use CBD oil in many different ways. For example, apply it to the skin or add it to creams or lotions.

How does F.D.A. regulate CBD in cosmetics? 

In the U.S.A., the U.S. Food and Drug Administration (F.D.A.) does not prohibit or restrict the use of cannabis or cannabis-derived ingredients in cosmetics. It considers the possibility that a product containing these substances can have both makeup and drug use (for instance, creams to treat dermatitis or acne). Therefore, you should consider some essential factors before using CBD products: 

• Contain no more than 0.3% T.H.C.
• have proof of third-party testing by an ISO/IEC 17025-accredited laboratory
• make sure the product pass tests for pesticides, heavy metals, mold, and microbes
• make certain products pass the safety testings 
• are not from a company subject to an F.D.A. warning
• make sure the company provides certificates of analysis for the product

Collagen

What is collagen 

  Collagen is the most abundant protein in the human body that gives strength and elasticity to the skin. Collagen is a protein molecule made up of amino acids. 

Why can’t you just put collagen on your face?

Collagen can be entirely manufactured in the lab without any animal sources. That’s good news. The bad news is you can’t just put collagen on your face because it’s a massive structure that will not penetrate the cells. So the companies came up with the idea of creating collagen supplements. But here’s the big question, are they good for you or effective? 

Why are collagen supplements not effective on the skin?

 F.D.A. does not regulate collagen supplements. Most collagen U see in fancy supplements comes from animal sources like pigs or cows with added vitamins and proteins. Even tho collagen is a crude protein compared to other proteins in your body; it’s still a challenging process to 100 % make it in the lab. So if you are a fan of collagen supplements, remember it’s not F.D.A. approved, and get the most expensive and vegan one. 

Note: they might tell you F.D.A. does not regulate it because it’s a supplement and related to foodstuff, but that’s not true and not the reason. The best way to have more collagen in your skin structure is to use products that boost collagen production.

What product increases collagen production?

Collagen production happens through reactions between different peptides. Most anti-aging products contain lab-made peptides with a high penetration rate. When peptide concentration increases, your skin will produce more collagen to balance the reaction.  

 Fragrance

The fragrance combines chemicals that give each perfume or cologne (including those used in other products) its distinct scent.

Where do fragrances come from?

 Fragrance ingredients might come from petroleum or natural raw materials. Companies that manufacture perfume or cologne purchase fragrance mixtures from fragrance houses (companies that specialize in developing fragrances) to develop their proprietary blends. In addition to “scent” chemicals that create the fragrance, perfumes, and colognes contain solvents, stabilizers, U.V. absorbers, preservatives, and dyes. These additives are frequently, but only sometimes, listed on product labels.

Labeling 

In contrast, the chemical components in fragrance are protected as trade secrets and described on the label only as “fragrance.” In other personal care products, added fragrances also include a combination of ingredients that give the product a scent and stabilize the smell. These are typically only indicated by “fragrance” or “perfume.”

How to choose the best fragrance for your cosmetic products?

F.D.A. Regulations for Fragrance 

Fragrance ingredients in cosmetics must meet the exact requirement for safety as other cosmetic ingredients. The law does not require F.D.A. approval before they go on the market, but they must be safe for consumers when a customer follows the directions.

Current laws must provide the F.D.A. with authority to require disclosure or public safety of fragrance ingredients. In the U.S., companies need to list ingredients on the label; however, this regulation excludes the individual constituents of fragrance to preserve fragrance trade secrets. This sustains a loophole that leads to disclosure gaps. 

 International Fragrance Association 

The International Fragrance Association (I.F.R.A.) and the Research Institute for Fragrance Materials (R.I.F.M.) develop and set voluntary standards for chemicals in the “fragrance” component of products. The US, Canada, and Europe rely on I.F.R.A. and R.I.F.M. to identify ingredients for use in fragrance. In effect, this means the international Fragrance industry is self-regulating. You should always read labels and avoid products with no information other than “fragrance.”

Menthol 

Properties

The mint is considered a hospitality plant in ancient Greece and Greek mythology. And in ancient Egypt, it was sometimes used as a currency. One of the mint’s favorite properties is its refreshing smell. But there is interesting ongoing research in characterizing the minty smell more objectively. Some of the reasons for mint flavor and scent research are focused on detecting what scents consumers prefer. The scenting process hasn’t been as objectively analyzed compared to other plant traits perceived by senses like vision, taste, and sound. The main chemical component of mint oils is menthol and its oxidized relative, menthone. These components are associated with the refreshing feeling of mint plants. In the flavor industry, mint species’ values depend on their menthol content.

Mechanism 

 In our bodies, menthol elicits a cool sensation by selectively activating the TRPM8 channel. The TRPM8 track is humans’ primary molecular transducer of cold tomato sensation. Then, menthol binds to TRPM8, activating the cold sense in humans.

Additionally, the mint market is growing fast (Grandview Research, 2019). Due to such high demand, menthol is now usually synthetically produced. Nowadays, many products use synthetically made menthol for flavoring.

Health Concern

The International Fragrance Association (I.F.R.A.) lists 3,059 materials reported as being used in fragrance compounds. Some of these 3,059 ingredients have evidence linking them to health effects, including cancer, reproductive toxicity, allergies, and sensitivities. A 2016 study assessed the self-reported health effects of fragrance. This survey of a random sampleU.S.f U.S. residents found that 99.1% of participants are exposed to fragranced products at least once a week from their use, others’ use, or both. Participants also reported an extensive list of health effects experienced when exposed to fragrance ranging from migraines and asthma to gastrointestinal and cardiovascular problems. The findings showed that many participants did not know of the chemicals in fragrance and would not continue to use a fragranced product if they knew it emitted pollutants. 

Nano Silvers

Why is nano silver antibacterial?

Ag+ ions can attack the bacteria structure and penetrate and bind to the D.N.A. Then it will block the respiratory system and stop the cell’s energy production. Nanosilver is effective on both gram-positive and negative.

Is it Toxic?

When it comes to a human cell, it’s tough to say if they are toxic because the different Ag+ ion has a different impact. However, most of them penetrate the skin and go to the dermis. Also, studies examining its effect on human cells realized that aged ones aren’t toxic.

• Antioxidant Matcha + Hyaluronic Acid 
• Cleansing Coffee + Hyaluronic Acid 
• Hydrating Inositol (vitamin B8) + Hyaluronic Acid 
• Pore cleansing Brown Sugar + Hyaluronic Acid 
• Niacinamide + Hyaluronic Acid 
• Aloe Vera + Hyaluronic Acid 
• Glycolic Acid + Hyaluronic Acid 
• Fine Lines Preventive Frankincense + Hyaluronic Acid 

What are Colloidal silvers?

 Difference between nano silvers and colloidal silvers

Nano silvers are the more advanced version of nanoparticles compared to colloidal silver. The critical difference between nanosilver and colloidal silver is the particle size. Nanosilver refers to the nanoparticles of silver having a particle size between 1 and 100 nm. In contrast, colloidal silver refers to the silver particles having a particle size higher than 100 nm suspended in a liquid.

Size

Colloidal silver is more extensive, so the penetration and antibacterial effect are less; for example, nanosilver is effective on biofilm bacteria( bacteria on your teeth), but colloidal silver isn’t

Capping agent

A capping agent is used to stabilize the nanoparticles. Because there is no capping agent in colloidal silver production, it’s unstable and can fall apart quickly.

Is colloidal silver safer to use?

There are so many benefits when using nano silvers in skincare. The most effective area is to treat infections. However, it’s not approved by the government because some studies prove it will cause damage to the D.N.A. of the cells, so please be careful when it comes to using nanoparticles in the skincare or food industry.

Overall Safety

Anyways, they need to be safer. They have a significant effect on your lungs if you inhale. That’s why they are not allowed to use them in masks or some other cosmetic products. They are excellent and super valuable for different industries; however, they can still cause damage to human cells. Now the importance is how they use these particles in the structure.

Parabens

Overview 

Parabens in cosmetics are preservatives that stop the growth of bacteria and increase the shelf life of the cosmetic product, but why is it harmful? Parabens are harmful due to disrupting the hormones in the body.

• Aloe Vera + Hyaluronic Acid 
• Fine Lines Preventive Frankincense + Hyaluronic Acid 
• Hydrating Inositol (vitamin B8) + Hyaluronic Acid 
• Pore cleansing Brown Sugar + Hyaluronic Acid 
• Cleansing Coffee + Hyaluronic Acid 
• Niacinamide + Hyaluronic Acid 
• Antioxidant Matcha + Hyaluronic Acid 
• Glycolic Acid + Hyaluronic Acid 
• Aloe Vera + Hyaluronic Acid 
• Fine Lines Preventive Frankincense + Hyaluronic Acid 

Why is Paraben banned in some countries?

 They can disrupt hormones in the body. Imbalanced hormones can harm fertility and reproductive organs, affect birth outcomes, and increase cancer risk. Parabens in cosmetic products can also cause skin irritation. 

Different types of Parabens

• How many forms of Paraben do we have?

We have so many forms of Paraben, but one of the most commonly used is methylparaben.

F.D.A. Rules and Regulations for Parabens

• How does F.D.A. regulate Preservatives?

F.D.A. doesn’t regulate preservatives such as Parabens. The law treats them the same as other cosmetic ingredients. 

Where is Paraben used?

1.Parabens in cosmetics 

Some Cosmetic products contain different types of Parabens. The longer-chain Parabens are more harmful than the short-chain. Propyl- and butyl- are examples of longer-chain Parabens.

2. Personal Products 

Personal care products are the most significant contributors to Paraben exposure. Women with more makeup products have more Paraben in their urine test than those who don’t use makeup products such as sunscreen or lotions. 

3. Cosmetic Companies 

Since 2006 Many cosmetic companies have used them in skin care products. Most formulations’ concentration ranges from 0.01 to 0.3%, but some companies use higher concentrations. 

Why is Paraben harmful?

• How does it harm the body?

Scientific studies prove their estrogenic activity. They act like the hormone estrogen in the body and cause endocrine. Also, it disrupts the normal function of hormone systems affecting reproductive system functioning.

Salycilic Acid 

What is salicylic acid?

Salicylic acid’s primary usage is in acne treatment. However, it doesn’t directly affect the acne bacteria. It works by unclogging the pores, which leads to more clear skin. Salicylic acid reaches deep into your pores to remove dead skin and extra oil.

How does S.A. clean pores?

• S.A. acts as an exfoliator. However, the process is more complicated than removing dead cells. It increases the amount of moisture in the skin; then, it dissolves the substance that causes the skin cells to stick together. This process makes it easier to shed skin cells. As a result, s.a. Can reach deeper into the pores. 

Is S.A. safe for the skin?

S.A. is overall safe for the skin; however, it can cause dryness and irritation due to removing too much oil. You should avoid using S.A. products if you have oily skin.

How is S.A. produced?

S.A. production can be done through a different mechanism. The most common one is via the Kolbe-Schmitt process. in this process, phenol and sodium hydroxide react to make sodium phenoxide. The phenoxide will come into contact with CO2 to form sodium salicylate. The last step is to acidify salicylate to get S.A. 

Other uses of S.A.

The primary use of S.A. is treating acne; however, other ruses include dandruff, psoriasis, seborrheic dermatitis of the skin and scalp, calluses, corns, common warts, and plantar warts, depending on the dosage in the formulation. 

What’s the difference between salicylic acid and Benzoyl Peroxide?

S.A. only targets a cause of acne, but Benzoyl Peroxide kills the acne bacteria itself. S.A. does not kill bacteria. Most acne treatments use both of these chemicals in combination. 

Talc Powder

 what is Talc powder?

Talc is a naturally occurring mineral. It includes elements like magnesium, silicon, and oxygen. 

 What is the use of talc powder?

Talc absorbs moisture. Cosmetic products such as baby powder, adult body, and facial powders like setting powder might include talc powder.

• Fine Lines Preventive Frankincense + Hyaluronic Acid 
• Hydrating Inositol (vitamin B8) + Hyaluronic Acid 
• Cleansing Coffee + Hyaluronic Acid 
• Niacinamide + Hyaluronic Acid 
• Aloe Vera + Hyaluronic Acid 
• Pore cleansing Brown Sugar + Hyaluronic Acid 
• Antioxidant Matcha + Hyaluronic Acid 
• Glycolic Acid + Hyaluronic Acid 

 Is talc powder safe?

Talc powder is safe but can be harmful if it includes Asbestos. Both talc and Asbestos are naturally occurring minerals. Unlike talc, however, Asbestos is a known carcinogen when inhaled. It’s hard to differentiate these two and requires expensive tests and clinical trials. 

 Why is Asbestos harmful?

Asbestos is a naturally occurring fibrous silicate mineral. There are six types, all composed of long and thin fibrous crystals, each fiber being collected of many microscopic “fibrils” that can be released into the atmosphere by abrasion and other processes. Breathing asbestos fibers may increase the risk of several serious diseases, including asbestosis, mesothelioma, and lung cancer. 

 Is it safe to use a product that includes Talc powder?

Do not use a product that includes Talc powder. If you do, check if they did the clinical testing to ensure the product has no asbestos. These two compounds have a similar structure, and differentiating them is challenging and expensive. Companies don’t have to test if the product is considered cosmetic (in the U.S.A.). Also, please note that some products might consider drugs in the U.S.A. Companies must deal with F.D.A., but they manufacture in a country where the same product is considered cosmetic and then import them to the U.S.A. That way, they can go through the required testing to ensure there is no asbestos in their product, which is very expensive and time-consuming.

Vitamin C 

Solubility 

Ascorbic acid is a water-soluble vitamin. This means that it dissolves in water. Because of solubility, it goes to the body’s tissues but is not well stored, so it must be taken daily through food or other supplements.

Different forms

Due to the instability, companies use different methods to stabilize it, and that’s why we see so many different products. But which one is the best?

Penetration

It is a charged molecule which makes it hard to penetrate. The process starts by reducing its P.H. with a specific method, making it more stable and eliminating the charge on the molecule so that it would penetrate more to the skin.

Which one is the best?

Bc of different stabilizing methods, you see so many products out there. But the most beneficial form is :

L-ascorbic acid

Side Effects 

Serum

Some side effects might be when using V.C. on your skin in serum forms. The most common side effects of using vitamin C on your skin can be skin irritation, redness, and itching, but this mostly happens to sensitive skin.

Supplements

The safe upper limit is 2,000 milligrams a day. Taking too much can cause side effects, including:

• Nausea, vomiting, and diarrhea.
• Heartburn.
• Stomach cramps or bloating.
• Fatigue and sleepiness, or sometimes insomnia.
• Headache.
• Skin flushing.