Tretinoin Metabolism and Energy Expenditure: What the Evidence Actually Shows

At a glance

• Drug / topical tretinoin (all-trans retinoic acid)
• Label / Renova (tretinoin cream 0.02%) [1]
• Approved use on that label / adjunct for fine facial wrinkles; does not eliminate wrinkles or repair sun-damaged skin [1]
• Skin absorption / 1% to 31% across topical formulations; less than 2% for the 0.05% emulsion in healthy men [1]
• Energy expenditure / the label contains no energy expenditure, weight, or metabolic-rate data
• Main label cautions / local irritation and photosensitivity [1]

Does topical tretinoin affect energy expenditure?

The Renova label contains no energy expenditure, body weight, or metabolic rate data. Its controlled trials measured facial wrinkling, pigmentation, roughness, and laxity over 24 weeks [1].

What the label says about absorption

The Renova label reports transdermal absorption of tretinoin from various topical formulations ranged from 1% to 31% of the applied dose, depending on healthy versus dermatitic skin [1]. No percutaneous absorption study was conducted with Renova 0.02% in human volunteers, according to the label [1]. For a 0.05% oil-in-water emulsion, absorption was less than 2% after a single application in 7 healthy men and after repeated daily application for 28 days in 7 healthy men; bioavailability was lower after repeated application, and endogenous tretinoin concentrations did not differ significantly [1].

How the label describes tretinoin's activity

The label calls tretinoin an endogenous retinoid metabolite of vitamin A that binds RARα, RARβ, and RARγ [1]. It says it has not been established whether clinical effects are mediated through retinoic acid receptor activation, other mechanisms such as irritation, or both [1].

What is not supported

The Renova label does not list weight loss, obesity, or low energy expenditure as an indication. Its use is limited to fine facial wrinkles as an adjunct to skin care and sun avoidance, and it says the product does not eliminate wrinkles, repair sun-damaged skin, reverse photoaging, or restore more youthful skin [1]. Tretinoin is not approved or labeled for weight loss or metabolism.

What the label says to watch for

The Renova label calls the cream a dermal irritant and lists local erythema, pruritus, burning, stinging, and peeling. In vehicle-controlled studies of 339 patients, 32% of all study patients had skin irritation that was severe, led to temporary discontinuation, or led to use of a mild topical corticosteroid, and about 4% discontinued because of adverse reactions [1]. It says to keep the cream out of the eyes, mouth, angles of the nose, and mucous membranes, to avoid or minimize sunlight and sunlamps, and to use sunscreen (minimum SPF 15) and protective clothing [1]. The label says Renova should not be used with photosensitizing drugs (for example thiazides, tetracyclines, fluoroquinolones, phenothiazines, sulfonamides) because of possible augmented phototoxicity, and should not be used if the patient is pregnant, attempting to become pregnant, or at high risk of pregnancy [1].

Frequently asked questions

›Does tretinoin affect metabolism or energy expenditure?

The Renova label does not address energy expenditure, body weight, or metabolic rate. Its controlled trials measured facial wrinkling, pigmentation, roughness, and laxity, not metabolic outcomes [1].

›How much tretinoin is absorbed through the skin?

The Renova label reports 1% to 31% absorption across topical formulations, depending on healthy versus dermatitic skin. For the 0.05% emulsion, less than 2% was absorbed after single and repeated daily application in 7 healthy men each [1].

›What does the label say about pregnancy?

The Renova label says not to use the cream if the patient is pregnant, attempting to become pregnant, or at high risk of pregnancy. Its contraindications section lists a history of sensitivity reactions to any component [1].

References

1. U.S. National Library of Medicine, DailyMed. Renova tretinoin cream 0.02% (Bausch) prescribing information. Renova tretinoin cream 0.02% (Bausch) label