Emi-lyn, tässä kopsaus englanniksi A-vitamiinijohdannaisista
Retinol, Retinoids, and Tretinoin: What's the Difference?Retinol (the entire vitamin A molecule) can be broken down into more potent compounds, which are referred to as retinoids. Although the terms vitamin A, retinol, and retinoid often are used interchangeably, each has its own distinctive actions and regulations. For example, some forms of retinol can be used freely in cosmetics, while others (retinoids) can be obtained only by prescription.
We know it's confusing; following are a few points to help clarify it for you:
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* Retinol is a cosmetic ingredient that any cosmetics company can include in its products. It does not require a prescription. Other effective forms of cosmetic-grade vitamin A that you'll see in cosmetics include retinyl acetate, retinyl palmitate, and retinaldehyde, among others.
* Retinol is effective because when absorbed into your skin, it is broken down and converted into retinoic acid. Retinoic acid is the compound that actually can affect skin cells and their behavior.
* Both the cosmetic forms and the prescription forms of vitamin A can cause irritation, but, as you would expect, the highest risk of irritation is with the prescription forms (retinoids). * You can reduce or eliminate the irritation caused by retinol by using effective skin-care products that do not contain irritating ingredients.
* Prescription retinoids include retinoic acid (also called tretinoin), the active ingredient in Renova and Retin-A; adapelene, the active ingredient in Differin; and tazarotene, the active ingredient in Tazorac.
* All forms of retinol have similar, although not identical, functions and provide truly impressive benefits for skin, which explains their popularity in the world of skin care.
Eli vaikka reseptivahvuinen retinoidi (joihin siis tretinoiini kuuluu) on tietysti vahvin, ei se tarkoita, että muista muodoista ei ole mitään hyötyä: mahdolliset haitatkin eli ihon ärtyminen, hilseily, punoitus jne. ovat myös vastaavasti pienempiä ja haittavat elämää vähemmän.
C-vitamiinin stabiiliudesta täällä
* The forms of vitamin C that are proven most stable and effective are: ascorbic acid, L-ascorbic acid, ascorbyl palmitate, sodium ascorbyl phosphate, retinyl ascorbate, tetrahexyldecyl ascorbate, and magnesium ascorbyl phosphate.
* Regardless of marketing hype – there is no one “best” form of topically-applied vitamin C.
* A proven range for vitamin C efficacy is between 0.3% and 10%.
* All antioxidants, including vitamin C, are vulnerable to deterioration in the presence of air and light. If a product containing antioxidants does not come in airtight, opaque packaging, don’t buy it!
Vaikutuksista
* Protect skin cells and skin’s support structure from UV-related damage
* Improve the appearance of sun-damaged skin
* Strengthen skin’s barrier response
* Reduce inflammation
* Promote collagen production
* Enhance effectiveness of peels and microdermabrasion
* Lessen hyperpigmentation (at levels of 5% or greater)
* Boost the efficacy of sunscreen actives
Jauheen stabiiliudesta en menisi vannomaan. Olen lukenut joittenkin säilytävän itsetekemäänsä seerumia jääkaapissa ja käyttävän sitä viikkojenkin päästä, mutta ehkä helpommalla pääsee valitsemalla laadukkaan seerumin suoraan. ellie sitten halua paneutua kotikemistin uraan kunnolla ja rueta eksperimentoimaan eri säilöntöaineilla jne...
Yksi itselläni ei-ärsyttäväksi osoittautunut C-seerumi on La Roche Posayn Active C (myydään ainakin pharmazon.gr) - ei ole keltaiseksi värjättyä..
PS. iHerb.com myy esim Avalon Organicsin Lavender Renewal Facial Serum, jossa ei onneksi ole laventelia paljonkaan, mutta Ceetä Magnesium Ascorbyl Phosphaten muodossa
