What Is Calcium Hydroxymethionine?
Calcium Hydroxymethionine is the cosmetic name for calcium bis[(±)-2-hydroxy-4-(methylthio)butyrate], a calcium salt derived from the amino acid methionine. In its purified form it appears as a fine white powder that dissolves easily in water-based solutions. Because it contains both calcium and a methionine-like structure, it offers mild skin-conditioning properties without adding heavy oils or waxes.
The ingredient first drew attention in animal nutrition, where it was used to supply methionine for healthy growth. Formulators later noticed its gentle hydrating effect on skin, leading to experimental trials in topical products in the early 2000s. Today it is produced through a controlled fermentation process that converts plant-sourced sugars into hydroxy-methylthio butyric acid, which is then neutralized with food-grade calcium hydroxide. The result is a stable, high-purity powder suitable for cosmetic use.
You’ll most often find Calcium Hydroxymethionine in lightweight moisturizers, soothing face masks, after-sun lotions and anti-aging serums that aim for a non-greasy feel. Its compatibility with water-based formulas also makes it popular in toners, essences and sheet masks where quick absorption is a priority.
Calcium Hydroxymethionine’s Cosmetic Benefits/Uses
In skincare formulations Calcium Hydroxymethionine serves a single but valuable role:
As a skin-conditioning agent it helps maintain a smooth, soft skin surface by binding water to the upper layers of the epidermis. This mild hydration can improve texture, reduce the appearance of flakiness and support the skin barrier without leaving residue, making it suitable for daily use in both leave-on and rinse-off products.
Who Can Use Calcium Hydroxymethionine
This gentle, water-soluble ingredient is considered suitable for every major skin type including dry, normal, combination, oily and sensitive. Because it delivers lightweight hydration without occlusive oils it benefits oily or acne-prone skin, yet its barrier-supporting calcium helps soothe dryness and sensitivity. No specific skin type is known to react poorly to the ingredient when it is correctly formulated.
Calcium Hydroxymethionine is synthesized from plant-derived sugars and neutralized with mineral calcium, so it contains no animal-based raw materials. This makes it compatible with vegan and vegetarian lifestyles provided the finished product also meets cruelty-free standards.
Current research shows no ingredient-related concerns for women who are pregnant or breastfeeding. That said, this is not medical advice and anyone who is pregnant or nursing should review all skincare products with a qualified health professional before use.
The ingredient does not increase photosensitivity. Standard daily sunscreen practices are still recommended but no extra sun precautions are required specifically because of Calcium Hydroxymethionine.
Potential Side Effects/Adverse Reactions
Individual responses to topical Calcium Hydroxymethionine can vary. The points below outline potential side effects yet most people will not experience them when the ingredient is used correctly in a well-formulated product.
- Mild redness or irritation in those with extremely reactive skin
- Transient tingling during first few uses, typically subsides quickly
- Contact dermatitis if a person is specifically allergic to methionine derivatives, which is rare
- Stinging on broken skin when applied over fresh cuts or abrasions
If any uncomfortable reaction occurs discontinue use and consult a healthcare professional for further guidance.
Comedogenic Rating
Rating: 0
Calcium Hydroxymethionine is fully water-soluble and leaves no oily film on the skin, factors that dramatically reduce its ability to block pores. It is used at low concentrations and lacks fatty acids or waxy components typically linked to breakouts, so it earns the lowest possible score on the comedogenic scale.
This makes the ingredient suitable for people who are prone to acne or frequent breakouts.
Because it is usually paired with other light, hydrating ingredients, formulas containing Calcium Hydroxymethionine tend to remain non-comedogenic as a whole unless heavier additives are introduced elsewhere in the product.
Summary
Calcium Hydroxymethionine is a gentle, water-based skin conditioner that binds moisture to the upper layers of the skin, smooths texture and offers mild barrier support thanks to its calcium content. It performs these roles without adding grease or weight, making it a versatile option for moisturizers, serums, toners and masks.
The ingredient is still relatively niche compared with better-known humectants like glycerin or hyaluronic acid, yet formulators appreciate its light feel and vegan compatibility so its popularity is slowly rising.
Safety data show a low risk of irritation when the compound is properly formulated and used as directed. As with any new skincare ingredient it is wise to perform a patch test on a small area of skin before adding a product containing Calcium Hydroxymethionine to your regular routine.