Retinoids Ranked: From Retinyl Palmitate to Tretinoin

Not all retinoids are created equal. The term covers a family of vitamin A derivatives with vastly different potencies, evidence bases, and effects on skin. Understanding where each retinoid sits in the hierarchy helps you choose appropriately for your skin’s tolerance and your goals.

The Retinoid Conversion Pathway

All retinoids must eventually become retinoic acid (tretinoin) to exert their effects on skin. The pathway looks like this:

Retinyl esters → Retinol → Retinaldehyde → Retinoic Acid (Tretinoin)

Each conversion step requires enzymatic activity and results in some loss of potency. The further an ingredient is from retinoic acid in this chain, the less predictably it converts and the weaker its effects.

This doesn’t mean weaker retinoids are useless — it means they’re gentler, require more patience, and suit different situations.

The Ranking

Tier 1: Prescription Retinoids

Tretinoin (Retinoic Acid)

What it is: The active form of vitamin A. No conversion required — it works directly on retinoid receptors.

Strength: The gold standard. Decades of research support its efficacy for photoageing, acne, and hyperpigmentation.

Evidence: Extensive. Peer-reviewed studies demonstrate measurable improvements in wrinkles, skin texture, pigmentation, and collagen production.

Irritation potential: High, especially initially. Dryness, peeling, redness, and sensitivity are common during the adjustment period (often called “retinisation”).

Availability: Prescription only in the UK. Available in concentrations from 0.01% to 0.1%.

Best for: Those serious about anti-ageing who can tolerate irritation and access prescriptions.

Tazarotene

What it is: A synthetic retinoid (not naturally occurring) that converts to tazarotenic acid.

Strength: Potentially more potent than tretinoin for some conditions.

Evidence: Strong for acne and psoriasis; less cosmetic-focused research than tretinoin.

Irritation potential: Very high — often more irritating than tretinoin.

Availability: Prescription only.

Best for: Primarily acne treatment under dermatological supervision.

Adapalene

What it is: A synthetic retinoid that binds directly to retinoid receptors.

Strength: Similar efficacy to tretinoin for acne; less research on anti-ageing.

Evidence: Strong for acne. Growing evidence for anti-ageing, though less than tretinoin.

Irritation potential: Lower than tretinoin. Often better tolerated.

Availability: Prescription in the UK, though available over-the-counter in some countries.

Best for: Acne-prone skin; those who can’t tolerate tretinoin.

Tier 2: High-Potency Over-the-Counter

Retinaldehyde (Retinal)

What it is: One conversion step from tretinoin. Converts directly to retinoic acid.

Strength: The strongest OTC retinoid. Some studies suggest comparable efficacy to low-concentration tretinoin.

Evidence: Moderate. Fewer studies than tretinoin, but research supports efficacy for photoageing and acne.

Irritation potential: Moderate to high. Can cause significant irritation, though generally less than tretinoin.

Availability: Over-the-counter, though less common than retinol. Often more expensive.

Best for: Those wanting maximum OTC potency; transitioning toward prescription retinoids; those who find retinol too weak.

Tier 3: Standard Over-the-Counter

Retinol

What it is: Two conversion steps from tretinoin. Must convert to retinaldehyde, then to retinoic acid.

Strength: The most common OTC retinoid. Effective, but requires higher concentrations than tretinoin for similar effects.

Evidence: Good. Multiple studies demonstrate improvements in photoageing, though effect sizes are typically smaller than tretinoin at comparable timelines.

Irritation potential: Moderate. The conversion process buffers potency, making retinol gentler. Still causes irritation in sensitive individuals.

Availability: Widely available in products from 0.1% to 1%+.

Best for: Most people starting retinoids; maintenance after achieving results with stronger forms; those with moderate sensitivity.

Tier 4: Entry-Level and Gentle Options

Retinyl Propionate

What it is: An ester form of retinol, requiring multiple conversion steps.

Strength: Weaker than retinol. Evidence is limited.

Evidence: Minimal. A few studies suggest some efficacy, but far less research than retinol.

Irritation potential: Low.

Availability: Occasionally found in products marketed as gentle retinoids.

Best for: Those who react to everything and want retinoid exposure with minimal risk.

Retinyl Palmitate

What it is: The most common retinyl ester. Three conversion steps from tretinoin.

Strength: The weakest commonly used retinoid. Conversion to active form is inefficient.

Evidence: Very limited for anti-ageing. Studies struggle to demonstrate meaningful cosmetic benefits.

Irritation potential: Very low — largely because activity is very low.

Availability: Very common in products marketed as “gentle” or for beginners.

Best for: Honestly, not much. It provides retinoid in name only. Most people would be better served by starting with low-concentration retinol.

Special Categories

Hydroxypinacolone Retinoate (HPR / Granactive Retinoid)

What it is: A retinoic acid ester that may bind directly to retinoid receptors without conversion, though this mechanism is debated.

Strength: Claimed to be as effective as retinol without irritation. Reality is unclear.

Evidence: Very limited. Primarily in vitro and brand-sponsored studies. Independent research is lacking.

Irritation potential: Very low.

Availability: Found in products marketing gentle retinoid activity.

Best for: Those who want to try retinoids with minimal irritation risk. Efficacy is uncertain.

Bakuchiol

What it is: Not a retinoid at all — a plant-derived compound (from Psoralea corylifolia) that may act on similar pathways.

Strength: Limited. One study found it comparable to retinol; this hasn’t been replicated widely.

Evidence: Minimal. Promising early results, but far less research than any true retinoid.

Irritation potential: Very low.

Availability: Widely marketed as a “natural alternative” to retinoids.

Best for: Those who can’t use retinoids during pregnancy or breastfeeding; those who want to avoid retinoids but want something in that category. Temper expectations.

Concentration Comparisons

Direct concentration comparisons are difficult because conversion efficiency varies. However, rough equivalences:

0.025% tretinoin ≈ 0.5-1% retinol (very roughly)
0.05% tretinoin ≈ 1%+ retinol
0.1% tretinoin > any OTC retinol concentration

These are approximations. Individual skin metabolism affects conversion rates significantly.

Choosing Your Level

Start with retinol if:

You’ve never used retinoids
Your skin is moderately sensitive
You want results without prescription access
You’re building a long-term routine

Consider retinaldehyde if:

Retinol works well but you want more
You can’t access prescriptions
You’re willing to pay a premium for OTC
Your skin tolerates retinol without issues

Move to tretinoin if:

You want maximum proven efficacy
You can tolerate the adjustment period
You have access to prescriptions
You’re serious about addressing photoageing

Stay with gentle forms if:

You have genuinely reactive skin
You’ve tried retinol repeatedly and can’t tolerate it
You’re using other sensitising treatments
You’re pregnant or breastfeeding (in which case, most retinoids should be avoided entirely)

Using Retinoids Effectively

Regardless of which retinoid you choose:

Start slowly. Begin 2-3 times weekly and increase as tolerated.

Buffer if needed. Applying over moisturiser reduces irritation (and somewhat reduces efficacy — a reasonable trade-off during adjustment).

Moisturise well. Retinoids impair barrier function during adjustment. Support your skin.

Use sunscreen religiously. Retinoids increase photosensitivity. This isn’t optional.

Be patient. Visible results typically take 12+ weeks. Tretinoin studies showing significant improvement often run 6-12 months.

Accept some irritation. Mild dryness and flaking during the first weeks is normal. Severe burning, persistent redness, or worsening over time is not.

The Honest Assessment

Tretinoin remains the most proven retinoid for anti-ageing. Nothing OTC matches its evidence base.

Retinol is a legitimate, effective option for those without prescription access or who can’t tolerate tretinoin.

Retinaldehyde sits between them — stronger than retinol, gentler than tretinoin — but less research than either.

Retinyl esters (palmitate, etc.) provide marginal benefit at best. They’re often included to put “retinoid” on a label without delivering meaningful activity.

Novel retinoids (HPR, etc.) are interesting but unproven. They may work; they may not. The evidence doesn’t yet support confident recommendations.

The best retinoid for you is the strongest one your skin can tolerate, used consistently over time. A gentle retinoid used nightly beats a potent one used once monthly because of irritation.

Choose according to your skin, your access, and your patience. Then stick with it long enough to actually see results.