Main Navigation

The Definitive Guide to Retinoids

Retinoids are the most researched and effective group of ingredients in skincare. They range from gentle over-the-counter serums, creams or gels to potent prescription products. The reason retinoids are so popular is because of their broad range of actions including treating acne, fading hyperpigmentation and softening the fine lines and texture changes of ageing skin. The only catch is that there are so many different types of retinoids and they vary enormously in strength. In fact, choosing the wrong one for your skin is all too common and usually the reason people either see no results or give up due to irritation. This guide explains what retinoids are, how they work and their uses. We compare the different types of in terms of strength and what they treat. Learn how to choose between them and .

What are Retinoids?

Retinoids are a family of . They all do broadly the same job in the skin, but they differ in potency and how many steps it takes them to work. This their effectiveness, side effect profile and whether you need a prescription. It helps to split retinoids into two groups:

One thing to clarify is that all too often when people say "retinoid" they often mean the prescription kind. When they say "retinol" they usually mean the milder over-the-counter kind. However, this isn’t actually the case. Retinol is just the basic form of Vitamin A and is the most commonly available over-the-counter. All retinoids are derivatives of Vitamin A. So else that isn’t Retinol is a retinoid.

How Do Retinoids Work for Skin?

Every retinoid ultimately works by turning into the same thing; retinoic acid (aka ). This is the only form the skin can actually use directly. Retinoic OnabotulinumtoxinAAbobotulinumtoxinAIncobotulinumtoxinAPrabotulinumtoxinALetibotulinumtoxinARimabotulinumtoxinBHyaluronic Acid FillersCalcium Hydroxylapatite FillersPoly-L-lactic Acid FillersPolymethylmethacrylate FillersAutologous Fat GraftingForehead Lines TreatmentGlabellar Frown Lines TreatmentCrow's Feet TreatmentBunny Lines TreatmentChemical Brow LiftLip FlipGummy Smile CorrectionMasseter ReductionJaw SlimmingDimpled Chin SmoothingCobblestone Chin SmoothingNefertiti Neck LiftMicro-BotoxMesotoxHyperhidrosis TreatmentChronic Migraine ReliefBruxism TreatmentTMJ TreatmentCervical Dystonia TreatmentNeck Spasm TreatmentBlepharospasm TreatmentLip AugmentationLip ContouringCheekbone EnhancementTear Trough FillersNasolabial Fold SofteningMarionette Line FillersLiquid RhinoplastyNon-Surgical Nose JobJawline ContouringJawline DefinitionChin AugmentationTemple VolumisingHand RejuvenationAcne Scar Subcision Filling binds to receptors in your skin cells and changes how they behave. It speeds up , stimulates collagen production and helps unclog pores. This is what makes the whole family effective across acne, pigmentation and ageing.

The difference between the retinoids comes down to how far each one sits from that active form. The weaker, over-the-counter retinoids have to be by the skin in a series of steps before they can work. Each step loses some along the way, which is why a retinyl ester (three steps away) is far weaker than retinaldehyde (one step away). Prescription tretinoin skips the queue entirely, because it is acid. and tazarotene are synthetic retinoids that also bind the receptors directly without needing conversion. This is the single most useful thing to about retinoids. The fewer conversion steps, the more potent and faster-acting the retinoid. However, it also makes it more likely to irritate the skin.

The Retinoid Strength Ladder

The retinoid runs in a fixed order. Retinyl esters convert to retinol, retinol converts to retinaldehyde and retinaldehyde to retinoic acid. Because potency tracks so closely with how close each is to retinoic acid, the family forms a clear ladder from gentlest to strongest. The strength tiers (from lowest to highest) are:

is also a newer prescription which probably sits somehwere between adapalene and . It is the only topical retinoid licensed for acne use on the body. Sitting outside this ladder is (the active in Accutane and Roaccutane). It is a prescription oral retinoid reserved for severe or treatment-resistant acne. Isotretinoin works throughout the body rather than just on the skin and has a number of serious possible side effects. It requires close monitoring throughout treatment.

What Do Retinoids Treat?

The reason retinoids are so widely prescribed is because they increase turn-over of skin cells which stimulates collagen building, texture and unclogs pores. This mechanism of action can help address several of the most common skin concerns at once. Retinoids are useful treatments for:

At City Skin Clinic, retinoids (and tretinoin in particular) are among the ingredients we prescribe most often. They form the backbone of many of our custom , , and treatments.

Which Retinoid is Right for You?

With so many options, the right retinoid depends on three things. These are your skin’s sensitivity, the concern you are treating and your goals. As a general approach these are our top tips for choosing which retinoid to start on:

The most common mistake is jumping straight to the strongest retinoid available. A retinoid you can actually tolerate and use consistently will always beat a stronger one that the skin. This can cause skin barrier damage, post-inflammatory hyperpigmentation and even drive you to give up.

How to Use Retinoids & the Retinisation Period

reward patience and consistency and they punish impatience with irritation. Whichever one you use, the principles are the same. Start on the lowest strength that makes sense for your skin, apply it only two or three times a week at first, and build up the frequency as your skin adjusts. Use a pea-sized amount for the whole face at night, and always follow with a daily . This is because all retinoids make the skin more sensitive to UV damage.

The first few weeks are where most people struggle. As the retinoid speeds up cell turnover, it can trigger a period of dryness, redness, flaking and sometimes a temporary increase in breakouts. This adjustment period is called retinisation and the breakout part is . These are common things people can encounter and not a sign that the treatment is failing. This period usually within 4 to 6 weeks, and it is worth knowing how to tell . your with a good moisturiser through this phase makes a real difference, and some people prefer to to buffer it and reduce irritation. If you are still struggling with adapting after a couple of months, our post on covers the usual reasons.

Also, a word on combining retinoids with other . Retinoids pair well with some ingredients and clash with others, so it is worth knowing before layering them with acids or other .

Retinoid Side Effects & Safety

Retinoids are powerful, and most people experience some side effects, especially early on. The good news is that the common ones are manageable and tend to ease as the skin builds tolerance. The typical side effects are:

There is also a persistent myth worth addressing. The strength of a retinoid does not determine its so much as your ability to use it . This is also why retinol was rather than an outright ban.

Who Cannot Use Retinoids?

Generally speaking, suit most people with proper and approriate use. However, as with anything in life, they’re not for everyone. Below are some of the situations where you should either avoid or be more cautious:

How to Get Prescription Retinoids in the UK

Over-the-counter retinoids like retinyl esters, retinol and retinaldehyde are freely available in cosmetic products throughout the UK. However, prescription retinoids are a different matter. You can only get them through a doctor or other qualified prescriber who has assessed your skin and decided they are safe and appropriate for you. Any website or clinic selling prescription retinoids without a consultation is not a source. Historically this meant an in-person dermatology . Now you can also through a number of telehealth clinics which offer online and treatment if appropriate.

At City Skin Clinic, we believe skincare should be personal. We use topical retinoids like alongside other actives where appropriate following an online consultation with one of our doctors. They will review your skin, concerns and medical history to create a bespoke plan suitable for your needs. You can read more about our for , , and , or to start your journey to great skin today.

This article is for general and does not constitute medical advice. Prescription retinoids are prescription-only medicines and should be used only under the supervision of a qualified . Always read the patient information leaflet and report any suspected side effects to the MHRA via the Yellow Card scheme.

What is the difference between a retinoid and a retinol?

Which is the strongest retinoid?

Do I need a prescription for a retinoid?

Which retinoid should a beginner start with?

How long do retinoids take to work?

Are retinoids safe in pregnancy?

Can I use a retinoid with vitamin C or acids?

Authored by:

The to great skin starts here. Start your online consultation for personalised prescription-strength skincare.

Supported payment methods

Follow us

Copyright © 2026 City Skin Clinic - City Skin Clinic and The Modern Salon brought to you by Brainworks Interactive Ltd. registered in England No. .