Chemically, tretinoin is all-trans-retinoic acid, also known as (all-E)-3,7-dimethyl-9-(2,6,6-trimethyl-1-cyclohexen-1-yl)-2,4,6,8-nonatetraenoic acid. Tretinoin is a retinoid and a metabolite of naturally occurring Vitamin A. Tretinoin has a molecular weight of 300.44, a molecular formula of C 20 H 28 O 2 and the following chemical structure: RETIN-A MICRO (tretinoin) gel is for topical use. Each gram of RETIN-A MICRO gel: • 0.04%, contains 0.4 mg of tretinoin • 0.06%, contains 0.6 mg of tretinoin • 0.08%, contains 0.8 mg of tretinoin • 0.1%, contains 1 mg of tretinoin The formulation contains methyl methacrylate/glycol dimethacrylate crosspolymer (MICROSPONGE ® System), propylene glycol dicaprylate/dicaprate and butylated hydroxytoluene. Other components consist of benzyl alcohol, butylated hydroxytoluene, carbomer 974P, cyclomethicone and dimethicone copolyol, disodium EDTA, glycerin, PPG-20 methyl glucose ether distearate, propylene glycol, purified water, sorbic acid, and trolamine. Tretinoin Chemical Structure

RETIN-A MICRO ® is indicated for the topical treatment of acne vulgaris in adults and pediatric patients 12 years of age and older. RETIN-A MICRO is a retinoid indicated for the topical treatment of acne vulgaris in adults and pediatric patients 12 years of age and older. ( 1)

Gel (white to very pale yellow and opaque): • 0.04% (0.4 mg of tretinoin per gram) • 0.06% (0.6 mg of tretinoin per gram) • 0.08% (0.8 mg of tretinoin per gram) • 0.1% (1 mg of tretinoin per gram). Gel: 0.04%, 0.06%, 0.08%, and 0.1%

For topical use only. Not for oral, ophthalmic, or intravaginal use. • Prior to RETIN-A MICRO use, thoroughly cleanse area(s) with a mild, non-medicated cleanser then pat the skin dry. • When applying RETIN-A MICRO, keep away from the eyes, the mouth, paranasal creases of the nose, and mucous membranes. • Apply a thin layer of RETIN-A MICRO (0.04%, 0.06%, 0.08%, or 0.1%) to skin where acne lesions appear (cover the entire affected area), once daily in the evening. Do not apply more than a thin layer . Improvements in acne lesions may be noticed after two weeks of RETIN-A MICRO therapy, but more than seven weeks of therapy may be needed for sustained benefit. If RETIN-A MICRO was temporarily discontinued due to local adverse reactions, RETIN-A MICRO therapy may be resumed upon resolution of local adverse reactions. • For topical use only. Not for oral, ophthalmic, or intravaginal use. • Keep away from eyes, mouth, paranasal creases of the nose, and mucous membranes. • Apply a thin layer of RETIN-A MICRO to skin where acne lesions appear (cover the entire affected area) (0.04%, 0.06%, 0.08%, or 0.1%) once daily in the evening.

• Local Skin Irritation : RETIN-A MICRO can cause local skin irritation, including excessive dryness, redness, swelling, peeling, itching, blistering, burning, or stinging • Avoid use on eczematous skin or during weather extremes, such as severe wind or cold. • To reduce the risk of local skin irritation, wash the treated skin gently, using a mild, non-medicated soap, avoid washing the treated skin too often or scrubbing it hard when washing, and apply a topical moisturizer. • If severe local skin irritation occurs, discontinue use temporarily or permanently. • Initial Worsening of Inflammatory Acne Vulgaris : During the early weeks of RETIN-A MICRO treatment, an apparent exacerbation of inflammatory lesions may occur. If RETIN-A MICRO is tolerated, this should not be considered a reason to discontinue therapy. • Photosensitivity : RETIN-A MICRO can cause photosensitivity. Advise patients to avoid or minimize unnecessary exposure to UV light, including sunlight and sunlamps. Advise patients to use sunscreen (SPF ≥15) and sun-protective clothing if UV light exposure cannot be avoided. Avoid use on sunburn skin. 5.1 Local Skin Irritation RETIN-A MICRO can cause local skin irritation, including excessive dryness, redness, swelling, peeling, itching, blistering, burning, or stinging . Use of RETIN-A MICRO in greater than the recommended dosage (more frequent than once daily application or excessive application) will not result in more rapid or improved acne results and may result in marked redness, peeling, or discomfort. Tretinoin has been reported to cause severe local skin irritation on eczematous skin. Weather extremes, such as severe wind or cold, may increase the risk of skin irritation in patients using RETIN-A MICRO. To reduce the risk of local skin irritation, instruct RETIN-A MICRO-treated patients to: • Avoid use of RETIN-A MICRO in areas affected by eczema. • Minimize or avoid use of RETIN-A MICRO with weather extremes. • Wash the treated skin gently, using a mild, non-medicated soap, pat it dry, and avoid washing the treated skin too often or scrubbing it hard when washing. RETIN-A MICRO is not recommended with concomitant use of medicated or abrasive soaps and cleansers, products that have a strong drying effect, products with high concentrations of alcohol, astringents, spices, or lime peels. • Apply a topical moisturizer. Advise patients that concomitant use of topical over the counter (OTC) acne products containing benzoyl peroxide, sulfur, resorcinol, or salicylic acid with RETIN-A MICRO may increase the risk for local skin irritation including dryness, erythema, and peeling. Consider withholding the use of topical OTC acne products if signs of skin irritation develop. Advise patients to allow the skin irritation effects of the topical OTC acne products to subside before initiation of RETIN-A MICRO treatment. If severe local skin irritation occurs, discontinue RETIN-A MICRO use temporarily or permanently. Efficacy of RETIN-A MICRO at reduced frequencies of application has not been established

Initial Worsening of Inflammatory Acne Vulgaris During the early weeks of RETIN-A MICRO treatment, an apparent exacerbation of inflammatory acne vulgaris lesions may occur. If RETIN-A MICRO is tolerated, initial worsening of inflammatory acne vulgaris lesions should not be considered a reason to discontinue therapy

Photosensitivity RETIN-A MICRO can cause photosensitivity. Advise patients to avoid or minimize unnecessary exposure to ultraviolet (UV) light, including sunlight and sunlamps, while using RETIN-A MICRO. Advise patients with sunburn to not use RETIN-A MICRO until the sunburn fully recovers. Advise patients, especially those who may be required to have extended periods of UV light exposure (e.g., due to occupation or sports), those with inherent sensitivity to the sun, or those using drugs that cause photosensitivity, to use sun protection daily in the form of sunscreen (sun protection factor [SPF] ≥ 15) and sun-protective clothing, when UV exposure cannot be avoided, even on days when it is not sunny or inside activities are expected.