Tretinoin (Topical)

Structure: All-trans retinoic acid, the acid form of vitamin A and the endogenous ligand for retinoic acid receptors. Applied topically at 0.01% to 0.1%, it normalises keratinocyte turnover, unplugs comedones, and with long-term use increases dermal collagen. It is the same molecular family as Isotretinoin (Accutane) but the route of administration changes everything about the risk profile.

Dosage:

• Starting: 0.025% cream, a pea-sized amount for the entire face, 2-3 nights per week
• Building: increase frequency to nightly over 4-8 weeks as tolerated
• Stepping up: move to 0.05% or 0.1% only once 0.025% is tolerated nightly and results have plateaued
• Applying more product or more often does not accelerate results. It only causes irritation, which people then quit over.

Administration:

• Apply at night to clean, completely dry skin. Damp skin increases penetration and irritation, so wait 20-30 minutes after washing.
• Moisturiser before or after (buffering) reduces irritation without meaningfully reducing efficacy
• Daily sunscreen is mandatory. Retinoids increase photosensitivity, and unprotected sun exposure undoes the photoageing benefit you are paying for.
• Do not layer in the same application with benzoyl peroxide or strong AHA/BHA acids. Alternate nights instead.
• For truncal acne, apply only to affected areas rather than treating the whole back and chest.

Key Notes:

• Well suited to the mild to moderate comedonal steroid acne that does not justify an oral retinoid. It works on follicular plugging, not on the androgenic driver.
• The retinisation period (roughly weeks 2-6) brings peeling, redness, and often an initial worsening of acne. This is expected, not failure. Reduce frequency rather than abandoning the treatment.
• Systemic absorption is negligible. Topical tretinoin does not produce the lipid deterioration, transaminase elevation, or musculoskeletal effects of oral isotretinoin, and it does not require the oral drug's monitoring burden.
• Pregnancy: prescribing practice still treats topical retinoids as contraindicated, and that caution should be respected, even though measured systemic exposure sits orders of magnitude below teratogenic thresholds.
• Treating a large body surface area (full back and chest, common on cycle) increases total absorption relative to facial use. It still does not approach systemic retinoid dosing, but it is a reason to keep application targeted.
• Severe nodulocystic or extensive truncal steroid acne generally will not clear on topical tretinoin alone and needs an oral agent.
• Not hormonal, not suppressive, and no interaction with AAS, peptides, GH, or any ancillary.

Bloodwork Monitoring:

• No routine bloodwork is required or useful. Systemic exposure is too low to move any standard marker. Lipids, liver enzymes, hormones, glucose, and haematology are all unaffected.
• If acne is the reason you are using it, the informative bloods are the ones explaining the acne rather than anything about the drug: Total Testosterone, Free Testosterone, DHT, Oestradiol, SHBG, and Prolactin.
• Any lipid or liver derangement in someone using topical tretinoin comes from elsewhere in the protocol. Do not attribute it to the cream, and do not stop the cream expecting the panel to improve.