Why is Mars Bar non-veg?

November 9, 2025 •

3 min read

In 2007, a public outcry forced UK-based Mars to reverse a decision to use animal extracts in their chocolate bars, but the confusion continues. The simple question, "Why is Mars Bar non-veg?" actually has a nuanced answer involving historical recipe changes, regional variations, and the distinction between vegetarian and vegan ingredients.

Quick Summary

This article explores the historical and regional factors behind the belief that Mars bars are non-vegetarian, clarifying past controversies involving animal rennet and distinguishing between vegetarian and non-vegetarian ingredients. It highlights how the ingredients and labeling have evolved, making many modern Mars bars vegetarian-friendly in some regions, though not vegan due to dairy.

Key Points

2007 Controversy: The belief that Mars bars are non-veg originated from a 2007 incident where UK products contained animal-derived rennet in the whey ingredient.
Recipe Reversal: Due to public pressure, Mars swiftly reversed its decision and re-certified its popular bars as suitable for vegetarians in the UK and other markets.
Not Vegan: Current Mars bars are not vegan because they contain milk solids (like milk powder, whey, and lactose) and egg white powder in the nougat.
Regional Variations: Ingredient formulations can differ significantly depending on the country of production, so always check the label for the most accurate information.
Labeling Matters: Modern packaging often explicitly states if a product is "Suitable for Vegetarians," which helps clarify its status for concerned consumers.
Distinguishing Diets: The confusion highlights the difference between vegetarianism (allows dairy and eggs) and veganism (excludes all animal products).

The 2007 Controversy: Animal Rennet and the Public Outcry

The perception of Mars bars being non-vegetarian largely originates from a 2007 controversy in the UK. At that time, Mars announced a recipe change for certain chocolate products, including Mars and Snickers, to use whey containing trace amounts of animal rennet, an enzyme from calf stomachs. This decision sparked significant backlash from vegetarians and animal welfare groups.

The Fallout and Swift Reversal

The strong public reaction led Mars to quickly reverse its decision within a week, apologizing and committing to making their popular bars suitable for vegetarians again. Despite this, the incident created a lasting impression, contributing to the belief that Mars bars are non-veg.

The Real Reasons Modern Mars Bars Are (Sometimes) Non-Veg

Beyond the resolved 2007 rennet issue, other ingredients can make a Mars bar non-vegetarian or, more commonly, non-vegan, depending on the region.

Milk Derivatives: The Primary Non-Vegan Ingredient

Milk chocolate contains several animal-derived ingredients that are unsuitable for vegans, though acceptable for most vegetarians. These include:

Skimmed milk powder
Milk fat
Lactose and whey powder

Egg White Powder in the Nougat

The nougat center often contains egg white powder. While this is fine for ovo-vegetarians, it makes the product non-vegan. This highlights the difference between vegetarian and vegan diets.

Potential for Cross-Contamination

Mars and other manufacturers may state that products could contain traces of allergens like nuts due to shared equipment. For strict vegans, cross-contamination with dairy is also a consideration.

Global Variations in Mars Bar Ingredients

Mars bar ingredients can vary significantly by country, meaning suitability for vegetarians can differ globally. Recipes and sourcing are not uniform across all regions. Checking local product labels is essential.

The Evolving Landscape of Food Labeling

Increased consumer demand has led to more transparent food labeling. Manufacturers provide more details on allergens and dietary suitability, but consumers should still carefully read labels as formulations can change.

Comparison: Mars Bar vs. Other Confectionery


Feature	Mars Bar	Gummy Candies (Traditional)	Vegan Chocolate Bar
Key Non-Vegan Ingredients	Dairy (Milk, Whey), Egg White Powder	Gelatin (from animal bones/skin)	None (uses plant-based alternatives)
Texture	Soft, chewy nougat and caramel	Chewy, elastic	Varies (often smooth and creamy with plant-based milks)
Primary Sweetener	Sugar, Glucose Syrup	Sugar, Glucose Syrup	Sugar, fruit extracts, etc.
Dietary Suitability	Vegetarian (not vegan)	Not Vegetarian or Vegan	Vegan and Vegetarian
Manufacturing History	2007 controversy over animal rennet	Traditional ingredient, now widely replaced in vegetarian versions	Gaining popularity with rising demand for plant-based products

The Final Verdict on the Mars Bar

The perception of Mars bars being non-veg largely stems from a past UK incident involving animal rennet, which has since been resolved. Modern Mars bars are typically suitable for vegetarians but not vegans due to milk and egg products. Regional variations in ingredients exist, so checking the label is crucial. The enduring confusion highlights the difference between vegetarian and vegan diets and the impact of historical controversies.

How to Check if Your Mars Bar is Vegetarian

To confirm if a Mars bar is suitable for your diet:

Read the label: Look for a "Suitable for Vegetarians" label.
Check ingredients: Look for non-vegetarian items like gelatin or animal rennet. Modern versions should use vegetarian-sourced whey.
Consider the region: Ingredients can vary by country.
Know your diet: Understand that vegetarian allows milk/eggs, while vegan does not. Mars bars are not vegan due to dairy and egg white powder.

Reading labels is the best way to determine a Mars bar's dietary suitability.

Frequently Asked Questions

Yes, following the 2007 controversy, Mars UK reversed its recipe change and re-certified its main bars as suitable for vegetarians. However, it is always best to check the specific product label, especially if purchasing from a different country, as regional variations exist.

A vegetarian product is made without meat, poultry, or fish, but can contain animal byproducts like milk and eggs. A vegan product contains no animal products or byproducts whatsoever. Mars bars are typically vegetarian because they contain milk and egg white powder, but they are not vegan.

Animal rennet is an enzyme derived from the stomach linings of young calves, traditionally used in cheesemaking. Its use in Mars products became controversial because it meant the chocolate bar was no longer suitable for vegetarians, many of whom were unaware the change had been made.

No, ingredient formulations can vary by country due to regional sourcing and regulations. This is why it is important to read the label on the product you are purchasing to ensure it meets your dietary standards.

Egg white powder is used as an ingredient in the nougat center of the Mars bar to help achieve its characteristic soft, chewy texture. It acts as a foaming agent and stabilizer.

Yes, with the rise of plant-based eating, many brands now offer vegan chocolate bars that replicate the texture and flavor of traditional candy bars. These use ingredients like plant-based milk and agar-agar instead of dairy and eggs.

The controversy is still relevant because it created a lasting perception among some consumers that Mars bars are not vegetarian. Even though the recipe was reversed, the memory of the incident continues to influence public opinion and raises questions about the brand's dietary suitability.