Tretinoin Buying Guide: Strengths, Generics & How to Order Safely

✓ Medically reviewed by  ·  Last reviewed: May 2026

Morgan Ellis

Pharmacy Researcher · 8 years experience

Pharmacy researcher with 8 years reviewing clinical drug information, generic formulation equivalence, and international pharmaceutical standards. Focuses on patient-facing accuracy in medication education.

Reviewed by Sophie Carter, MPharm — last reviewed 11 May 2026

What is tretinoin and why does it need a guide?

Tretinoin is a first-generation retinoid — a vitamin A derivative that binds directly to retinoic acid receptors in the skin. Unlike over-the-counter retinol (which your skin must convert to retinoic acid first, losing 95% of potency in the process), tretinoin is the active form. It works.

What it actually does inside the skin:

• Accelerates epidermal turnover — pushes skin cells through their cycle in 28 days instead of the 40–60-day sluggish rate that produces congestion and uneven tone.
• Clears micro-comedones — comedogenic lesions that sit below the surface for 30–90 days before becoming visible acne. Tretinoin dismantles them before they erupt.
• Stimulates dermal collagen — 12+ months of nightly use produces measurable type-I collagen increases and reduces fine-line depth. No other topical molecule has this depth of biopsy-confirmed evidence.
• Disperses melanin clusters — reduces post-inflammatory hyperpigmentation (PIH) and solar lentigines by slowing melanin transfer from melanocytes to keratinocytes.

The reason it needs a buying guide is simple: in most Anglophone markets it’s prescription-only, which means patients either pay $200+ for a branded tube or never start. International generic versions (A-Ret, Retino-A, Tretinex) are manufactured in WHO-GMP certified Indian pharmaceutical plants, are bioequivalent to Retin-A, and cost $8–18 per tube. Knowing what to buy, what strength, and what format matters enormously.

The generic landscape — what’s actually available

All five are manufactured in Indian pharmaceutical factories that hold WHO-GMP certification — the same international standard required for export to EU/UK markets. “Made in India” is not a quality flag; it’s the reason the molecule costs $10 instead of $200.

Gel vs cream vs microsphere — which format?

The active ingredient is identical across formats. The vehicle changes absorption speed, hydration, and irritation profile:

Gel (A-Ret, Tretinex): alcohol-based carrier dries quickly and delivers tretinoin more rapidly into the epidermis. Better for oily skin, active acne, and humid climates. More irritating during the retinization period. The clinical default for acne treatment.

Cream (Retino-A, Tretin): emollient base slows absorption slightly and provides a modest barrier boost. Better for dry or combination skin, anti-aging use, and full-face nightly application. Less irritating early on. The clinical default for photoaging treatment.

Microsphere gel (Retino-A Micro 0.04%): tretinoin is encapsulated in porous methyl methacrylate microspheres that release the molecule gradually overnight. Noticeably lower early irritation — often called the “sensitive skin tretinoin.” Efficacy equivalent to standard 0.025–0.04% cream at the same concentration; the release curve, not the molecule, is different. Best first-choice for retinoid-naive users or anyone who failed standard tretinoin twice due to irritation.

Which strength to start at

The most common mistake is starting too high. Irritation at 0.1% in week 2 doesn’t mean tretinoin doesn’t work — it means you started at the wrong strength.

• Retinoid-naive (never used Retin-A, adapalene, or retinol): start at 0.025% gel or cream, or Retino-A Micro 0.04% for sensitive skin. Run this for 12 weeks before considering a step-up.
• Previous adapalene/Differin user: your skin already handles retinoids. Starting at 0.05% is reasonable. Give it 8–10 weeks before evaluating.
• Anti-aging primary goal, no active acne: 0.025% cream is the dermatologist standard. Cream format adds hydration that supports the barrier while collagen remodeling begins.
• Experienced tretinoin user stepping up: 0.1% is the maximum strength. This strength significantly increases irritation without proportionally increasing benefit for most people — only a minority genuinely need it.

For a detailed strength comparison, see our tretinoin strengths guide (0.025% vs 0.05% vs 0.1%).

Protocol: the first 8 weeks

1. Week 1: Apply 3 nights only (Monday / Wednesday / Friday). Pea-size amount. Use the sandwich method — moisturizer first, tretinoin, moisturizer again — to buffer early irritation.
2. Weeks 2–3: Monday / Wednesday / Friday / Sunday (4 nights). Expect dryness and some peeling. This is normal.
3. Weeks 4–6: every other night. Skin is adapting.
4. Weeks 6–8: nightly if tolerating well. Some users need 10–12 weeks to reach nightly.
5. Ongoing: nightly as tolerated. Step up strength only after 12 weeks at current strength with comfortable tolerance.

What to expect — the tretinoin purge

Weeks 2–4 often bring a visible purge: existing micro-comedones surface simultaneously as skin turnover accelerates. This looks like a sudden breakout but is actually the skin clearing its backlog. It resolves. Most people who quit tretinoin do so at week 3, immediately before it starts working.

For a detailed timeline, see our tretinoin purge timeline guide.

What not to combine with tretinoin

• Benzoyl peroxide (same night): oxidizes tretinoin, reducing efficacy. Use BP in AM, tretinoin PM.
• AHAs/BHAs (same night): glycolic, lactic, salicylic acid all compound irritation. Use on alternate nights or in the AM.
• Vitamin C (same evening): pH mismatch and irritation stacking. Vitamin C belongs in the AM routine; tretinoin belongs in PM.
• Other retinoids: never layer retinol + tretinoin. One retinoid at a time.

Niacinamide (vitamin B3) is one of the very few actives that genuinely works well with tretinoin — it supports the skin barrier and reduces tretinoin-induced erythema. See our detailed guide on tretinoin and niacinamide compatibility.

SPF is non-negotiable

Tretinoin increases photosensitivity by thinning the stratum corneum. Skipping SPF undoes every benefit and accelerates the hyperpigmentation tretinoin was meant to fix. SPF 30 minimum, daily, even on cloudy days, for as long as you use tretinoin. See our tretinoin and sun exposure guide for the practical protocol.

How to order tretinoin generics from MedsBase

MedsBase stocks A-Ret Gel (all three strengths), Retino-A Cream, Retino-A Micro Gel, Tretinex Cream, and Tretin Cream — all manufactured under WHO-GMP certification. Orders ship worldwide in discreet packaging with no brand name visible. No prescription required in most destinations.

For a comparison of A-Ret vs Retino-A and the full format guide, see our A-Ret Gel & Tretinoin buying guide.

Written by

Sophie Chen

Pharmaceutical Content Researcher · 8 years experience

Sophie Chen is a pharmaceutical content researcher with 8 years covering generic medication access and clinical pharmacology. She specialises in international regulatory frameworks, bioequivalence standards, and patient-facing education on therapeutic drug classes. She is not a clinician.