Guides
Skincare, step by step
Practical answers to the questions that come up every day: what order to apply things, how much sunscreen is enough, how to read a label and how to tell whether a product is irritating your skin. Each guide gives the direct answer first, then the evidence and the limits.
All guides
Start with the question you have right now
Every guide is written from published dermatology guidance and research, uses plain language, and says clearly when something needs a clinician rather than a routine change.
57 guides, grouped by topic.
Routine basics
How Long Does Skincare Take to Work?
How long does skincare take to work? Sourced timelines for acne products, retinol, dark spots, melasma and sunscreen, and how to judge a product fairly.
Routine basicsHow Often Should You Exfoliate?
How often to exfoliate your face by skin type and exfoliant, from scrubs to AHAs and BHA, plus the warning signs that mean you are exfoliating too much.
Routine basicsHow to Introduce a New Skincare Product
How to add a new skincare product without guessing: one product at a time, how long to wait between additions, how long to judge results and reactions.
Routine basicsHow to Patch Test Skincare
How to patch test a new skincare product at home: where to apply it, how often, for how long, what a reaction looks like, and when you need a dermatologist.
Routine basicsSkincare Layering Order
The right order to apply skincare, morning and night: thinnest to thickest, treatments before moisturizer, sunscreen last, plus which actives not to stack.
Routine basicsWhat Is Double Cleansing?
Double cleansing means an oil or micellar step, then a gentle wash. Learn who actually needs it, how to do it in four steps, and when one cleanse is enough.
Routine basicsWhat Is Skin Cycling?
What is skin cycling? The four-night exfoliant, retinoid and recovery routine explained: what is sensible, what is untested, and how to adapt it to your skin.
Routine basicsWhat Is Slugging?
Slugging means sealing your night routine under a thin layer of petroleum jelly. Learn how it works, who it suits, who should skip it, and how to do it safely.
Using ingredients
Can Niacinamide Cause Breakouts?
Can niacinamide cause breakouts? It is not known to cause purging. Learn what new spots after starting it more likely mean, and how to work out the real cause.
Using ingredientsCan You Use AHA and BHA Together?
Can you use AHA and BHA together? Four safe ways to combine glycolic or lactic acid with salicylic acid, an example week, and who should stick to one acid only.
Using ingredientsCan You Use Glycolic Acid With Retinol?
Can you use glycolic acid with retinol? Why same-night use raises irritation, how to alternate nights safely, and who should not combine these two at all.
Using ingredientsCan You Use Retinol and Vitamin C Together?
Can you use retinol and vitamin C together? Why the usual split is vitamin C in the morning and retinol at night, when same-routine use works, and pH myths.
Using ingredientsCan You Use Retinol Every Day?
Can you use retinol every night? How to build up from a few nights a week, why nightly suits some people but not all, and the signs that you should slow down.
Using ingredientsCan You Use Retinol in Summer?
Can you use retinol in summer? Why you usually do not need to stop, how to adjust for sun, heat and holidays, and when to pause, such as after a sunburn.
Using ingredientsCan You Use Retinol With Niacinamide?
Can you use retinol with niacinamide? Why the pair is generally compatible, what research says about niacinamide and retinoid tolerability, and how to layer.
Using ingredientsCan You Use Salicylic Acid Every Day?
Can you use salicylic acid every day? It depends on the product type and your skin. How to tell if daily use suits you, signs of overuse, and how to cut back.
Using ingredientsCan You Use Vitamin C at Night?
Yes, you can use vitamin C at night. Learn why morning is the usual advice, when evening use makes more sense, and how to fit it around retinol.
Using ingredientsHow to Use Azelaic Acid
How to use azelaic acid: non-prescription vs prescription strengths, how to apply it, why it tingles at first, how long it takes, and what to know in pregnancy.
Using ingredientsHow to Use Benzoyl Peroxide
How to use benzoyl peroxide: which strength to start with, wash vs leave-on, short-contact use, avoiding bleached towels, managing dryness, and storage tips.
Using ingredientsHow to Use Glycolic Acid
How to use glycolic acid at home: which product to start with, how often, where it goes in your routine, how to step up strength, and what not to pair it with.
Using ingredientsHow to Use Hyaluronic Acid
How to use hyaluronic acid: whether damp skin really matters, why you should seal it with moisturizer, what to do in dry climates, and what the evidence shows.
Using ingredientsHow to Use Niacinamide
How to use niacinamide: how often to apply it, where it goes in your routine, what it pairs well with, and how many weeks studies took to show visible results.
Using ingredientsHow to Use Salicylic Acid
How to use salicylic acid for acne and clogged pores: which product type to pick, what strength, how often to apply, and when to take extra care with children.
Using ingredientsHow to Use Tranexamic Acid
How to use topical tranexamic acid for melasma and dark spots: where it goes in your routine, how often, what to pair it with, and how long to wait for results.
Using ingredientsHow to Use Vitamin C Serum
How to use a vitamin C serum: when to apply it, where it goes in your routine, how much to use, how to spot an oxidized bottle, and how to store it so it lasts.
Using ingredientsIs 10% Niacinamide Too Much?
Is 10% niacinamide too much? Most studies used 2% to 5%, and higher strengths are not proven to work better. Learn who should choose a lower strength and why.
Using ingredientsRetinol Before or After Moisturizer?
Should retinol go on before or after moisturizer? The usual order, when buffering or the retinol sandwich helps sensitive skin, and what the evidence shows.
Sunscreen
Does Sunscreen Expire?
Yes, sunscreen expires. Learn the FDA three-year rule, how to read expiry dates and the open-jar symbol, how heat damages it, and when to throw a bottle out.
SunscreenHow Much Sunscreen to Use
How much sunscreen to use on your face and body, which measuring rules are official and which are rough guides, and when and how to reapply it properly.
SunscreenHow to Choose a Face Sunscreen
Pick a face sunscreen that fits oily, dry, sensitive or acne-prone skin, melasma or deeper skin tones, and learn which label terms actually matter.
SunscreenIs SPF in Makeup Enough?
SPF foundation, powder and tinted moisturizer rarely protect as labeled, because people apply far too little. Learn why, and how to use SPF makeup properly.
SunscreenSunscreen Under Makeup
Where sunscreen goes in your makeup routine, how long to let it set, why SPF foundation or powder is not enough alone, and how to reapply over makeup.
Reading labels
Alcohol in Skincare
Not all alcohol in skincare is drying. Learn to tell alcohol denat. and ethanol from fatty alcohols like cetyl alcohol, and who may want to avoid them.
Reading labelsFragrance in Skincare
Fragrance in skincare: why it is a common skin allergen, fragrance-free vs unscented, EU allergen labeling rules, essential oils, and who should avoid it.
Reading labelsHow to Read a Skincare Ingredient List
Learn how to read a skincare ingredient list: INCI names, the order and 1% rules, Drug Facts on sunscreens, and which label claims have no legal meaning.
Reading labelsWhat Does Non-Comedogenic Mean?
What non-comedogenic means: why the claim is not regulated, how pore-clogging was tested, why ingredient lists mislead, and how to test products yourself.
Choosing products
Do You Need Eye Cream?
Eye cream is optional. See what it can realistically do for dryness, fine lines, puffiness and dark circles, what it cannot fix, and how to pick and apply one.
Choosing productsDo You Need Face Oil?
Face oil is optional. Learn what oils actually do, who benefits, who should skip them, which oils are gentler on the skin barrier, and how to use one properly.
Choosing productsDo You Need Toner?
Most people do not need toner. Learn when a hydrating or exfoliating toner adds something, when an alcohol astringent backfires, and how to use one safely.
Choosing productsHow to Choose a Cleanser
Choose a face cleanser by skin type: gel, cream, micellar, oil and medicated washes compared, gentle vs harsh surfactants, and how to wash your face properly.
Choosing productsHow to Choose a Moisturizer
Choose a moisturizer by skin type and concern: humectants, emollients and occlusives in plain words, label cues to look for, and when and how to apply it.
Skin health
How to Tell if a Product Is Irritating Your Skin
Learn the signs a skincare product is irritating your skin, how irritation differs from an allergy, what normal adjustment looks like, and when to see a doctor.
Skin healthSkincare During Pregnancy
Skincare during pregnancy: which ingredients dermatologists advise avoiding, which are generally considered acceptable, and how to handle melasma and acne.
Skin healthSkincare for Darker Skin Tones
Skincare for darker skin tones: why dark marks linger, why sunscreen still matters, gentle actives that help, and which peels, lasers and creams need caution.
Skin healthWhat Is the Skin Barrier?
What the skin barrier is, explained simply: the bricks-and-mortar outer layer, its key lipids, how water loss works, what damages it, and how to support it.
Product care
More guides
Comedogenic Ratings Explained: Are They Reliable?
Comedogenic ratings explained: where the 0 to 5 scale comes from, why rabbit-ear scores mislead, and how to judge oils like jojoba and squalane yourself.
More guidesHow Long Does Retinol Take to Work?
How long does retinol take to work? Realistic timelines for acne, texture, dark spots and fine lines, how long purging lasts, and when to switch strategy.
More guidesHow Often Should You Reapply Sunscreen?
How often should you reapply sunscreen? The 2-hour rule, what to do after swimming or sweating, indoor days, over makeup, and how much to use each time.
More guidesHow to Use Adapalene (Differin)
How to use adapalene (Differin): how much to apply, when, how to cut irritation, what to pair it with, and how long it takes to clear acne. Step-by-step.
More guidesHow to Use Retinol
How to use retinol step by step: a week-by-week start schedule, how much to apply, where it goes in your routine, how to buffer it and when to…
More guidesIs Hydroquinone Over the Counter?
Is hydroquinone over the counter? Not in the US since 2020. Learn why the CARES Act changed its status, what's prescribed now, safety and OTC alternatives.
More guidesIs Retinol a Prescription? Retinol vs Prescription Retinoids
Is retinol a prescription? No: retinol is sold over the counter. Learn which retinoids need a prescription in the US, how they differ and when to ask.
More guidesRetinol Side Effects and How to Manage Them
Retinol side effects explained: why dryness, peeling and redness happen, how long they last, how to calm them, and the signs that mean you should stop.
More guidesWhat Is Skin Purging?
What is skin purging? Which actives cause it, how long it lasts, how to tell it from a breakout or irritation, and how to get through it with…
More guidesWhat Not to Mix With Retinol
What not to mix with retinol: how AHAs, BHAs, benzoyl peroxide, vitamin C and scrubs interact, plus safe pairings and how to split your routine.
More guidesWhat Percentage of Retinol Should You Use?
What percentage of retinol should you use? Beginner to high strengths explained, the highest OTC retinol, and how to step up without irritation.
How we write guides
We start from dermatology guidance and published studies, then translate them into steps you can actually follow. When the evidence is thin or a popular rule is just convention, we say so instead of dressing it up.
Guides do not replace personal medical advice. Each one ends with clear signs that mean it is time to see a doctor or dermatologist.
A–Z index
Every guide on Skin Candid
Every guide, listed alphabetically, including the newest ones as they go live.
- Alcohol in Skincare
- Can Niacinamide Cause Breakouts?
- Can You Use AHA and BHA Together?
- Can You Use Glycolic Acid With Retinol?
- Can You Use Retinol and Vitamin C Together?
- Can You Use Retinol Every Day?
- Can You Use Retinol in Summer?
- Can You Use Retinol With Niacinamide?
- Can You Use Salicylic Acid Every Day?
- Can You Use Vitamin C at Night?
- Comedogenic Ratings Explained: Are They Reliable?
- Do You Need Eye Cream?
- Do You Need Face Oil?
- Do You Need Toner?
- Does Sunscreen Expire?
- Fragrance in Skincare
- How Long Does Retinol Take to Work?
- How Long Does Skincare Take to Work?
- How Much Sunscreen to Use
- How Often Should You Exfoliate?
- How Often Should You Reapply Sunscreen?
- How to Choose a Cleanser
- How to Choose a Face Sunscreen
- How to Choose a Moisturizer
- How to Introduce a New Skincare Product
- How to Patch Test Skincare
- How to Read a Skincare Ingredient List
- How to Store Skincare Products
- How to Tell if a Product Is Irritating Your Skin
- How to Use Adapalene (Differin)
- How to Use Azelaic Acid
- How to Use Benzoyl Peroxide
- How to Use Glycolic Acid
- How to Use Hyaluronic Acid
- How to Use Niacinamide
- How to Use Retinol
- How to Use Salicylic Acid
- How to Use Tranexamic Acid
- How to Use Vitamin C Serum
- Is 10% Niacinamide Too Much?
- Is Hydroquinone Over the Counter?
- Is Retinol a Prescription? Retinol vs Prescription Retinoids
- Is SPF in Makeup Enough?
- Retinol Before or After Moisturizer?
- Retinol Side Effects and How to Manage Them
- Skincare During Pregnancy
- Skincare for Darker Skin Tones
- Skincare Layering Order
- Sunscreen Under Makeup
- What Does Non-Comedogenic Mean?
- What Is Double Cleansing?
- What Is Skin Cycling?
- What Is Skin Purging?
- What Is Slugging?
- What Is the Skin Barrier?
- What Not to Mix With Retinol
- What Percentage of Retinol Should You Use?