Recall: hand sanitiser pulled from US shelves over hidden methanol
An alcohol-based hand sanitiser made in Mexico was recalled after testing found undeclared methanol. What happened, and the controls that prevent it.
Read article
Insights
Guidance for brands building cosmetics.
Regulation updates, the latest research, ingredient spotlights, recalls and safety alerts, market trends and stories from inside the CSL lab, written by CSL scientists.
Guires Cosmetic Science Lab
Explore the latest industry insights, market reports and customer case studies from Guires CSL scientists
Insights from the Guires CSL formulation, testing, clinical and regulatory teams: regulation updates, the latest research, ingredient spotlights, recalls and safety alerts, market trends and case studies, written to help brands make better product decisions.
Start your project with Guires CSL54 articles
No articles in this selection yet. The first pieces in this category are on the way: subscribe to hear when they are published, or ask the CSL team and we may write it next.
MoCRA for brands outside the US: what you need before you ship
Facility registration, product listing, US Agent, safety substantiation and adverse event reporting, in the order to tackle them.
Read article
“Dermatologically tested”: what the claim needs behind it
Patch tests, in-use studies and panel sizes, and how wording differs between markets.
Read article
Reformulating anti-dandruff shampoo after the EU zinc pyrithione ban
Permitted alternatives, how they perform, and what changes on the label.
Read article
One sunscreen, four markets: choosing UV filters that travel
Building a filter system accepted in the EU, US, Australia and ASEAN.
Read article
Cosmeceuticals in the UAE: cosmetic or drug?
How UAE authorities classify high-performance skin care, and how claim wording decides the route.
Read article
US consumer trends: skin-health ingredients in 2026
The ingredient themes shaping US skin-care briefs, and what each one means for formulation and claims.
Read article
Vitamin C in skin care: what the evidence shows for brightening
L-ascorbic acid and its derivatives are among the most studied brightening actives. Here is what recent trials show, how strong the evidence is, and how CSL formulation…
Read article
Niacinamide: the evidence behind a gentle, all-round brightening active
Niacinamide (vitamin B3) evens tone by a different route from most brighteners, and it is famously well tolerated. Here is what the trials show, from the landmark…
Read article
Glycolic acid: resurfacing, brightening and the evidence behind it
The smallest alpha hydroxy acid (AHA) penetrates fastest, which makes it the most effective for texture and the most likely to irritate. Here is what trials show and how…
Read article
Lactic acid: the gentler AHA that brightens and hydrates
Lactic acid exfoliates like glycolic acid but penetrates more slowly and helps the skin make its own barrier lipids. Here is the evidence, and why it suits dry and…
Read article
Licorice root extract: what the evidence really shows for tone and redness
Licorice is the most studied botanical for uneven tone, and its licochalcone A is a well-known soothing ingredient. The trials are small, so here is an honest look at…
Read article
Papaya enzyme (papain): gentle exfoliation, and what the evidence does not yet show
Papain is a popular “natural exfoliant”, but controlled human studies on the face are missing. Here is what is known, the allergy risk to manage, and how CSL formulation…
Read article
Allantoin in skin care: what the evidence shows for soothing skin
Allantoin is a long-used soothing and softening ingredient and, in the US, an approved skin protectant. Here is what the trials actually show, and how CSL formulation…
Read article
Alpha arbutin: what the evidence shows for dark spots and uneven tone
Alpha arbutin is a popular, gentle brightening active, but most human data come from small or combination studies. CSL formulation scientists explain the evidence, the…
Read article
Antioxidants in sunscreen: what the evidence shows, and what it doesn’t
Vitamin E, vitamin C and ferulic acid are often added to sunscreens. Human evidence that they add visible benefit is limited. Here is what is known and how CSL…
Read article
Azelaic acid: what the evidence shows for redness, marks and blemishes
Azelaic acid has strong trial evidence at medicine strength for redness, blemishes and uneven tone. CSL formulation scientists explain what that means for cosmetic…
Read article
Bakuchiol: what the evidence shows as a gentler retinol alternative
Bakuchiol is a plant-derived active often sold as a gentle alternative to retinol. Here is what the trials show, why the evidence is still thin, and how CSL formulation…
Read article
Bhringraj for hair: what the evidence shows for hair fall and thinning
Bhringraj is a classic Ayurvedic hair herb. Animal studies are promising, but human data come only from multi-herb oils and small open studies. CSL formulation…
Read article
Biotin for hair: what the evidence shows for hair fall and thinning
Biotin is sold widely for hair, mostly as a supplement. Reviews find no benefit without a deficiency, and high doses can distort blood tests. CSL formulation scientists…
Read article
Bisabolol in skin care: what the evidence shows for soothing skin
Bisabolol is a popular soothing ingredient from chamomile and candeia, but human trials of it on its own are few. CSL formulation scientists explain what the evidence…
Read article
Caffeine for hair: what the evidence shows for hair fall and fullness
Caffeine is the most tested cosmetic active for thinning hair, but most trials are small or industry-run. Here is what they show and how CSL formulation scientists use…
Read article
Centella asiatica: what the evidence shows for calming and skin repair
Centella asiatica, also called cica, is a popular soothing botanical. Here is what the small human studies show, how strong the evidence is, and how CSL formulation…
Read article
Ceramides in skin care: what the evidence shows for barrier repair
Ceramides are the main lipids of the skin barrier. Here is what trials show for dry and eczema-prone skin, how strong the evidence is, and how CSL formulation scientists…
Read article
Cosmetic clays: what the evidence shows for oil control and masks
Kaolin, bentonite and other clays soak up surface oil and give masks their texture. CSL formulation scientists explain what human studies show, why the effect is…
Read article
Climbazole: what the evidence shows for dandruff and flaking scalp
Climbazole is an azole antifungal used in anti-dandruff shampoos, usually alongside another active. Here is what the trials show and how CSL formulation scientists use…
Read article
Colloidal oatmeal: what the evidence shows for dry, itchy-feeling skin
Finely milled oats are one of the few botanicals recognised by the US FDA as a skin protectant. Here is what trials show for dryness and itch, and how CSL formulation…
Read article
Ferments in skin care: what the evidence shows for fermented ingredients
Galactomyces, bifida and lactobacillus ferments are popular in skin care. Controlled human evidence is patchy. Here is what exists and how CSL formulation scientists use…
Read article
Glutathione in skin care: what the evidence shows for brightening
Glutathione is a popular brightening ingredient, but topical trials are few and small. CSL formulation scientists explain what the evidence supports and how to keep this…
Read article
Glycerin in skin care: what the evidence shows for hydration and barrier
Glycerin is the workhorse humectant of skin care, with decades of controlled trials behind it. Here is what the evidence shows, how it compares with urea, and how CSL…
Read article
Hair-growth complexes: what the evidence shows for hair fall and fullness
Redensyl, Capixyl, Procapil and similar branded complexes are popular in hair serums. Human evidence is thin and mostly uncontrolled. CSL formulation scientists explain…
Read article
Hyaluronic acid: what the evidence shows for hydration and fine lines
Hyaluronic acid is the best-known hydrating active in skin care. Here is what controlled trials show, why molecular weight matters, and how CSL formulation scientists…
Read article
Iron oxides in tinted sunscreen: visible light and melasma evidence
Iron oxides give tinted sunscreens their colour and block visible light that UV filters miss. Here is what melasma trials show and how CSL formulation scientists build…
Read article
Kojic acid: what the evidence shows for dark spots and uneven tone
Kojic acid is a long-used brightening active with small trials and a new EU limit of 1%. CSL formulation scientists explain what the evidence supports and how to keep it…
Read article
Mild surfactants: what the evidence shows for gentler cleansing
Amino-acid surfactants, glucosides, betaines and biosurfactants are sold as gentler than SLS. Here is what human studies show, where the evidence is thin, and how CSL…
Read article
Onion extract for hair: what the evidence shows, and what it does not
Onion is a popular hair-care ingredient, but it rests on one small 2002 study in patchy hair loss. CSL formulation scientists explain what that study found and how to…
Read article
Panthenol (provitamin B5): what the evidence shows for skin barrier
Panthenol is a gentle humectant with decades of use in barrier and recovery care. CSL formulation scientists look at what recent studies show, where the evidence is…
Read article
Peptides in skin care: what the evidence shows for fine lines
Peptides are short amino-acid chains sold for smoother, firmer-looking skin. Here is what the trials show, why most are industry-funded, and how CSL formulation…
Read article
Piroctone olamine: what the evidence shows for dandruff and shedding
Piroctone olamine is a widely used anti-dandruff agent. Here is what the trials show, how strong they are, and how CSL formulation scientists use it within EU…
Read article
Postbiotic lysates: what the evidence shows for calmer, stronger skin
Postbiotics are inactivated bacteria or their by-products. Some have placebo-controlled trials for reactive and dry skin. Here is what they show and how CSL formulation…
Read article
Topical prebiotics: what the evidence shows for skin microbiome balance
Inulin and oligosaccharides are added to skin care to feed helpful skin bacteria. Human trials are few and small. Here is what they show and how CSL formulation…
Read article
Retinol and retinal: what the evidence shows for fine lines
Retinol and retinal are the best-studied cosmetic retinoids for fine lines. Here is what the trials show, where the evidence is thin, and how CSL formulation scientists…
Read article
Rosemary for hair: what the evidence shows for thinning and hair fall
Rosemary oil is one of the most talked-about hair ingredients, yet it rests on one human trial. Here is what that trial showed, its limits, and how CSL formulation…
Read article
Salicylic acid: what the evidence shows for blemishes, pores and scalp
Salicylic acid is the classic oil-soluble exfoliant for blemish-prone skin and flaky scalps. CSL formulation scientists review what recent trials show and where the…
Read article
Squalane in skin care: what the evidence shows for soft, supple skin
Squalane is a light, stable oil that mimics a lipid found in skin’s own sebum. Controlled trials of squalane alone are scarce. Here is what is known, and how CSL…
Read article
Sulphur in skin care: what the evidence shows for blemishes and flaking
Sulphur is one of the oldest actives for blemishes and dandruff. CSL formulation scientists found a small, mostly older evidence base, much of it testing sulphur…
Read article
Tea tree oil: what the evidence shows for blemishes and flaking scalp
Tea tree oil has small but real trial support for blemishes and flaking. New EU safety advice caps leave-on use far below trial levels. CSL formulation scientists…
Read article
Titanium dioxide in sunscreen: evidence, safety and EU inhalation rules
Titanium dioxide is a mineral UV filter strongest in the UVB range. Here is what the evidence and EU safety reviews say, and how CSL formulation scientists use it in…
Read article
Tranexamic acid: what the evidence shows for uneven skin tone
Topical tranexamic acid is a popular, gentle choice for dark patches and uneven tone. Here is what the trials show, how strong the evidence is, and how CSL formulation…
Read article
Urea in skin care: what the evidence shows for dry skin and barrier
Urea is part of the skin's own moisturising system and one of the best-tested humectants for dry, rough skin. Here is what trials show and how CSL formulation scientists…
Read article
Modern organic UV filters: what the evidence shows for daily sunscreen
Daily broad-spectrum sunscreen is one of the best-proven ways to slow visible skin ageing. Here is the trial evidence, the new US status of bemotrizinol, and how CSL…
Read article
Zinc oxide in sunscreen: what the evidence shows on safety and UV cover
Zinc oxide is a mineral UV filter that covers UVB and long UVA. Here is what human studies and regulators say, and how CSL formulation scientists turn it into sunscreens…
Read article
Zinc PCA: what the evidence shows for oily skin, blemishes and scalp
Zinc PCA is a staple of oil-control and blemish-care products. CSL formulation scientists found no trial of it on its own; the human data come from multi-active…
Read article
Zinc pyrithione: evidence for dandruff and where it is still allowed
Zinc pyrithione was the benchmark anti-dandruff active for decades but has been banned in EU cosmetics since 2022. Here is the evidence, the rules, and how CSL…
Read articleCategories
What we write about.
Ten themes, written by our formulation, regulatory, testing and product teams. Pick one to see its articles.
Case studies
Proof from real projects.
How CSL scientists solve real formulation and safety problems for clients. Published with client permission; client and product names are withheld under NDA.
Reverse engineeringDeformulating a benchmark body lotionBody lotion · Africa · 98% of the formula decoded with analytical chemistry and machine learning.98% of the formula decodedRead the case study
Technical benchmarkingBenchmarking a client’s new range against the marketThree client products · Canada · each benchmarked against multiple market references, without animal testing.3 client products benchmarked against multiple referencesRead the case study
Guides & webinars
Free resources.
MoCRA checklist
A one-page download of the MoCRA steps in our guide. Download the PDF
Webinars
Regulatory and claims webinars for brand teams. Subscribe below for dates.
Launch timeline calculator
Estimate how long your product will take, stage by stage.
Regulatory watch newsletter
Rule changes, before they hit your label.
A monthly email on new ingredient restrictions, MoCRA updates and market deadlines. Plus our free guides and webinar invitations.
Start a project
Create your next product with CSL.
Our formulation chemists, testing scientists and regulatory specialists work alongside your team, from the first brief to a market-ready product. Bring a brief, a benchmark or just an idea: a scientist will reply within one working day with next steps and an indicative scope.