An In-Depth Pharmacological Look: What is the Main Ingredient of Sudocrem?

October 9, 2025 •

3 min read

Trusted for over 90 years, the iconic grey pot of Sudocrem has a formula that remains largely unchanged since 1931 [1.4.3, 1.4.5]. So, what is the main ingredient of Sudocrem that gives it such enduring efficacy? The primary active component is zinc oxide [1.2.2, 1.3.3].

Quick Summary

The main ingredient of Sudocrem is zinc oxide, at a concentration of 15.25% [1.2.2]. This article explores how zinc oxide, along with lanolin and benzyl alcohol, creates a protective and soothing barrier for various skin conditions.

Key Points

Main Ingredient: The primary active ingredient in Sudocrem is zinc oxide, present at a concentration of 15.25% [1.2.2, 1.3.3].
Barrier Function: Zinc oxide creates a protective barrier on the skin, shielding it from irritants and moisture, which is key for treating diaper rash [1.3.1, 1.6.4].
Soothing Properties: The formula includes lanolin as an emollient to moisturize, and benzyl alcohol, which provides mild local anaesthetic and antiseptic effects [1.2.2, 1.5.3].
Versatile Uses: While famous for diaper rash, it's also used for eczema, acne, minor burns, cuts, and surface wounds [1.5.2, 1.5.5].
Historical Formula: Developed in Dublin in 1931 by pharmacist Thomas Smith, the formula has remained largely unchanged for over 90 years [1.4.3, 1.4.5].
Correct Application: For best results, apply a thin, translucent film to clean, dry skin rather than a thick, white layer [1.9.3, 1.9.5].
Supporting Ingredients: Benzyl benzoate and benzyl cinnamate are included for their recognized healing properties [1.2.1, 1.2.2].

A Dublin Original: The History of Sudocrem

Developed in 1931 by Dublin-based pharmacist Thomas Smith, Sudocrem has become a staple in households worldwide [1.4.3, 1.4.4]. Originally called "Smith's Cream," the name was later changed to "Sudocrem," derived from the Irish pronunciation of "soothing cream" [1.4.4, 1.4.5]. For over 90 years, the formula has remained a trusted remedy, still manufactured in Dublin, for a variety of skin complaints, most notably diaper rash [1.4.3, 1.3.1]. Its longevity is a testament to the effectiveness of its core components.

The Heart of the Formula: Zinc Oxide (15.25%)

The answer to 'what is the main ingredient of Sudocrem?' is zinc oxide [1.2.2, 1.3.3]. This white, powdered mineral compound is the powerhouse of the cream, making up 15.25% of the formula [1.2.2]. It is classified as a skin protectant and works in several ways [1.3.3].

How Zinc Oxide Works

Forms a Protective Barrier: When applied, zinc oxide creates a physical barrier on the skin's surface [1.6.4, 1.3.1]. This barrier shields the skin from moisture and external irritants, which is crucial for preventing and treating diaper rash caused by prolonged exposure to wetness [1.3.3].
Astringent Properties: Zinc oxide acts as a mild astringent, causing the tightening of skin tissues. This can help to reduce fluid loss from irritated or weeping skin [1.6.4].
Anti-Inflammatory and Antimicrobial: It possesses anti-inflammatory properties that help soothe redness and irritation associated with conditions like eczema, acne, and minor burns [1.6.4, 1.6.5]. Studies have also shown it has antimicrobial capabilities, inhibiting the growth of bacteria and helping to prevent infection in minor wounds [1.6.4, 1.5.3].

The Supporting Cast: Other Key Ingredients

While zinc oxide is the star, Sudocrem's effectiveness is enhanced by a synergistic blend of other ingredients [1.2.1, 1.2.2].

Lanolin (Hypo-Allergenic) - 4.00%

Lanolin is a natural emollient derived from sheep's wool that is remarkably similar to the skin's own oils [1.2.2, 1.7.3]. Its function is to moisturize and soothe the skin by locking in moisture and preventing water loss [1.7.3, 1.5.1]. A 2017 study noted that lanolin can help the skin retain 20-30% more water [1.5.1]. In Sudocrem, it helps to soften dry, chapped skin and complements the protective barrier of zinc oxide [1.5.1, 1.2.1].

Benzyl Alcohol - 0.39%

This ingredient serves multiple purposes. It acts as a mild local anaesthetic to soothe soreness and numb the pain associated with diaper rash or minor cuts [1.5.3, 1.5.5]. Additionally, it functions as an antiseptic, helping to prevent bacterial contamination of the wound and also acting as a preservative within the cream itself [1.2.1, 1.5.3].

Benzyl Benzoate (1.01%) and Benzyl Cinnamate (0.15%)

These components are recognized for their healing properties [1.2.1, 1.2.2]. They contribute to the cream's overall ability to help manage conditions like minor surface wounds and skin irritation [1.5.2].

Sudocrem vs. The Competition

How does Sudocrem stack up against other popular diaper rash creams? The main difference often lies in the primary active ingredient and overall formulation.


Feature	Sudocrem	Desitin Maximum Strength	Bepanthen Nappy Care
Main Active Ingredient	Zinc Oxide (15.25%) [1.2.2]	Zinc Oxide (40%) [1.8.2]	Dexpanthenol (5%)
Primary Action	Soothes and protects with a breathable barrier [1.3.1, 1.5.5]	Forms a thick, protective barrier for intensive treatment [1.8.2]	Supports skin's natural healing and recovery
Consistency	Thick cream, leaves a translucent film [1.9.3]	Very thick, opaque paste [1.8.2]	Lighter, ointment-like texture
Key Supporting Ingredients	Lanolin, Benzyl Alcohol [1.2.2]	Petrolatum, Lanolin [1.8.2]	Lanolin, Almond Oil

Proper Application for Best Results

To maximize Sudocrem's effectiveness, proper application is key. Less is often more.

Ensure the affected area is clean and dry [1.9.3].
Take a small amount of cream on the tip of your finger [1.9.5].
Gently massage the cream into the skin using light, circular motions. Avoid vigorous rubbing, especially on sore skin [1.9.3].
Aim to leave a thin, translucent film on the skin. If a thick white layer is visible, you have likely used too much [1.9.5].

Conclusion: A Time-Tested Formula

The main ingredient of Sudocrem, zinc oxide, is a powerful skin protectant with proven anti-inflammatory and barrier-forming properties [1.3.3, 1.6.4]. When combined with the emollient action of lanolin and the mild anaesthetic and antiseptic qualities of benzyl alcohol, the formula offers a multi-action approach to soothing and healing a wide range of minor skin complaints [1.5.2, 1.5.5]. From its origins as a humble "soothing cream" in a Dublin pharmacy, Sudocrem has earned its place as a trusted, versatile, and effective product for families around the globe [1.4.4, 1.4.3].

For more information on skin health, one authoritative source is the National Eczema Association.

Frequently Asked Questions

The main active ingredient in Sudocrem is zinc oxide, at a concentration of 15.25% [1.2.2, 1.3.3]. It acts as a skin protectant.

Yes, many people use Sudocrem as a spot treatment for acne. The zinc oxide and benzyl alcohol can help calm inflammation and reduce redness [1.5.1, 1.5.3]. However, because it can be occlusive, it may not be suitable for all skin types, especially oily skin [1.10.2].

Sudocrem is water-repellent. Its formula, containing oils and waxes along with zinc oxide, forms a protective barrier that helps to repel water and other irritants from the skin [1.5.4, 1.5.5].

The main difference is their active ingredient. Sudocrem is a zinc oxide-based barrier cream designed to soothe and protect, while Bepanthen's active ingredient is dexpanthenol, which focuses on supporting the skin's natural healing process.

Yes, Sudocrem contains 4% hypo-allergenic lanolin. It functions as an emollient, helping to soothe and moisturize the skin by preventing water loss [1.2.2, 1.5.1].

Benzyl alcohol is included in the formula for two main reasons: it acts as a mild local anaesthetic to help soothe pain and irritation, and it works as an antiseptic to help prevent bacterial infection [1.5.3, 1.5.5].

Sudocrem can be applied at every diaper change to help treat and soothe diaper rash. You should apply a thin layer to clean, dry skin as often as necessary [1.9.3, 1.3.3].