Retinol

The Basics On Retinol

What is Retinol?

Retinol, the name for the entire vitamin A molecule, is a skin-restoring ingredient and an antioxidant.

What are other names for Retinol?

3,7-DIMETHYL-9-(2,6,6-TRIMETHYL-1-CYCLOHEXEN-1-YL)-2,4,6,8-NONATETRAEN-1-OL, DRY FORMED VITAMIN A, RETINOL, RETINOL (VITAMIN A), and VITAMIN A

What is Retinol used for?

Of the retinoids, tretinoin appears to be the most potent and widely investigated as an antiaging agent1. There is an abundance of scientific research supporting the anti-aging benefits of retinoic acid for the skin1. Retinol is much less potent than retinoic acid or retinal in skincare treatment and it requires conversion by human keratinocytes to retinoic acid via retinal to achieve the same anti-aging skin results5. It has been suggested that retinol is less effective in the treatment of photoaged skin than retinoic acid or retinal due to the slow rate of oxidation of retinol to retinoic acid and retinal6. However, retinol has been shown to penetrate the skin more effectively then retinoic acid7. UVB Radiation depletes retinol and retinyl esters from the epidermis6. the reconstitution of both epidermal retinol and retinyl esters, after their depletion induced by UVB, was accelerated by previous topical treatment with retinaldehyde. It has been demonstrated that topical delivery of retinoids partly counteracts UVB-induced vitamin A depletion and promotes recovery6.

How Retinol is classified

Antioxidants, Vitamins, Skin-Restoring

Recommendations for using Retinol during pregnancy and breastfeeding

Can you use retinol while pregnant? Is retinol safe during pregnancy? Avoid

Retinol During Pregnancy

What we know about using Retinol while pregnant or breastfeeding

Can you use retinol while breastfeeding? Application of Vitamin A containing products may lead to excessively high and possibly unsafe levels of systemic Vitamin A. With regard to topical retinoids, there are isolated case reports that propose a link between typical retinoid embryopathy and topical tretinoin use.19–21 A prospective cohort study22 compared the rate of malformations among fetuses exposed and unexposed to tretinoin. The 94 tretinoin-exposed cases and their 133 controls were similar demographically, and pregnancy outcome did not differ between cases and controls. Overall, the use of topical retinoid in pregnancy may pose a small additional teratogenic risk, but more evidence is required. Until further information is available we would suggest that topical retinoids should be avoided in pregnancy.3 With regard to lactation, it is advised that systemic retinoids be avoided during breastfeeding; however, the amount of the drug in breast milk after topical application is probably too small to be harmful.1

FDA recommends that women of child-bearing age limit their intake of retinol to 5000 IU (1.5 mg retinol)/day. Source: FDA 1995. FDA Talk Paper: Vitamin A and Birth Defects. US Food and Drug Administration; In vitro and in vivo percutaneous absorption of retinol from cosmetic formulations: significance of the skin reservoir and prediction of systemic absorption. Source: Toxicol Appl Pharmacol 231(1): 117-21. Skin application of Vitamin A containing products may lead to excessively high and possibly unsafe levels of systemic Vitamin A. Source: Yourick JJ, Jung CT, Bronaugh RL 2008. In vitro and in vivo percutaneous absorption of retinol from cosmetic formulations: significance of the skin reservoir and prediction of systemic absorption. Toxicol Appl Pharmacol 231(1): 117-21. Female Ibm RORO (spf) rats (20 rats [test] and 10 controls; 12 weeks old) were used to investigate whether high oral doses of vitamin A (retinol) caused fetal malformations and the extent at which retinyl esters are transferred from the mother to the fetuses.77 Prior to mating, the control group was fed a basal diet that contained 4.5 x 103 RE/kg (1 retinol 16 equivalent [RE] = 1 µg retinol), and this diet was enriched with dry vitamin A palmitate type 500 (stabilized food industry product) containing 150.2 x 103 RE/g. Rats of both control and experimental groups had free access to food. In the experimental group, dietary vitamin A was stepwise increased to obtain retinyl ester concentrations of > 1525 nmol/ liter plasma before mating. Over an 8-month period prior to mating, vitamin A dosages of 15.2 x 103 RE/kg diet were fed for 40 days, 22.7 x 103 RE/kg diet were fed for 50 days, and the dose was increased to 45.5 x 103 RE for another 40 days and to 52.5 x 103 RE for 90 days. The mean body weights of experimental and control rats were not significantly different. All-trans, 13-cis, 4-oxo-all-trans, and 5,6-epoxy-all-trans retinoic acid vitamin A metabolites were determined in maternal and fetal plasma. Following high vitamin A intake, 4-oxo- and 5,6-epoxy retinoic acid concentrations were significantly higher in in the fetuses than in their mothers. Though high vitamin A intake by rat dams resulted in high maternal and fetal plasma concentrations of vitamin A and its metabolites, fetal malformations were not observed. The authors noted that this finding may be due to the fact that circulating retinyl esters are not teratogenic and that, after crossing the placental barrier, they are stored mainly in fetal liver.

General safety info about Retinol from CIR

A Cosmetic Ingredient Review (CIR) Final Report with the following conclusion was published 1987: On the basis of the available data presented in this report, the Expert Panel concludes that retinyl palmitate and retinol are safe as cosmetic ingredients in the present practices of use and concentration. Subsequently, at the June 13-14, 2005 CIR Expert Panel meeting, the Panel confirmed its original conclusion and agreed that the final report on retinyl palmitate and retinol should not be reopened. This decision, published in 2008, was based on a review of published and unpublished data that became available after publication of the final report in 1987.2 In the discussion section that established the basis for confirming the original conclusion, the Panel noted an ongoing National Toxicology Program (NTP) photococarcinogenicity study on retinyl palmitate and expressed interest in reviewing the results upon study completion. Public concern about the effects of retinyl palmitate in sunscreens have arisen. The Environmental Working Group (EWG)3 asserted that almost half of the sunscreens on the market contain retinyl palmitate (RP), and, based in the EWG’s interpretation of National Toxicology Program (NTP) study findings, EWG suggested that a health warning regarding the photocarcinogenic potential of sunscreens containing RP was appropriate. Media coverage has resulted in questions about the safety of sunscreens. The dermatology community has continued to support the need to use sunscreens.4 Thus, at the September 2012 Expert Panel meeting, the Panel deliberated on a re-review document that contained a summary of results from the 2011 NTP draft technical report on this study as well as other current data relating to the safety of retinol and retinyl palmitate in cosmetic products. After reviewing these data, the Panel determined that its safety assessment on retinol and retinyl palmitate should be reopened and also agreed that the new safety assessment should include the following additional ingredients: retinyl acetate, retinyl propionate, retinyl linoleate, retinyl oleate, retinyl rice branate, retinyl soyate, and retinyl tallate. Recognizing that retinoic acid was tested in the NTP study and its similarity to retinol and retinyl palmitate, the CIR staff subsequently agreed to add retinoic acid to this safety assessment. The NTP photocarcinogenicity study was subsequently published in August of 2012, and the results are summarized in this safety assessment.

Use this, not that!

Lactic acid, Maltic acid

Products where you might find Retinol

SkinMedica Age Defense Retinol Complex;Sunday Riley A+ High-Dose Retinoid Serum; Obagi Obagi360 Retinol; Drunk Elephant A-Passioni Retinol Cream; SUNDAY RILEY Luna Retinol Sleeping Night Oil; The INKEY List Retinol Anti-Aging Serum