Is the Impossible Burger Actually Vegan?

November 10, 2025 •

4 min read

According to the Vegan Society's definition, veganism seeks to exclude all forms of animal exploitation as far as possible and practicable. This principle lies at the heart of the debate over whether the Impossible Burger is actually vegan, with the controversy focusing on its use of animal testing.

Quick Summary

The Impossible Burger's vegan status is debated due to past animal testing on its heme ingredient for FDA approval, though its current ingredients are plant-based. The controversy pits the goal of reducing overall meat consumption against the core vegan principle of avoiding all animal exploitation.

Key Points

Animal Testing Controversy: A specific ingredient, soy leghemoglobin, was tested on rats for FDA approval, which many consider a violation of vegan principles.
All-Plant Ingredients: Despite its history, the finished Impossible Burger product contains only plant-based ingredients.
Ethical Divide: The debate pits utilitarian logic (saving more animals overall) against absolutist veganism (avoiding all animal exploitation).
Veganism Definition: The core issue stems from differing interpretations of what constitutes avoiding animal exploitation “as far as is possible and practicable”.
Individual Decision: Whether to eat an Impossible Burger is a personal choice based on an individual's ethical perspective regarding the animal testing.
Different to Beyond Burger: It is important to note that the rival Beyond Burger has not used animal testing.
Context Matters: A meat-eater using the product to reduce meat consumption may view it differently than a long-term vegan.

The Core Controversy: Heme and Animal Testing

At the center of the debate over whether the Impossible Burger is actually vegan is a single, unique ingredient: soy leghemoglobin, a type of heme. This genetically engineered molecule is produced via fermentation and gives the Impossible Burger its meat-like flavor, color, and aroma. While the ingredient itself is plant-based, its path to market involved animal testing.

The FDA Approval Process

To secure a Generally Recognized As Safe (GRAS) letter from the U.S. Food and Drug Administration (FDA) for this novel ingredient, Impossible Foods conducted animal tests. In 2017, after the FDA questioned initial safety data, the company commissioned a study involving feeding soy leghemoglobin to lab rats, which were later killed. The company argued that this was a necessary step to advance its mission of reducing the overall consumption of animal meat on a larger scale. This decision created a deep rift within the vegan community. For many, any product that has involved animal testing, regardless of the stated intention, cannot be considered truly vegan, as it violates the principle of avoiding animal cruelty.

Ingredients: What's in an Impossible Burger?

The current ingredients of the Impossible Burger are all plant-derived. They include:

Soy Protein Concentrate: Provides the meaty bite and texture.
Coconut Oil and Sunflower Oil: Give the patty its signature sizzle and juicy texture.
Natural Flavors and Yeast Extract: Enhance the savory, umami taste.
Methylcellulose and Food Starch: Act as binders to hold the patty together.
Vitamins and Minerals: Including Vitamin B12, zinc, and niacin, are added for nutritional value.
Soy Leghemoglobin (Heme): The controversial ingredient that mimics the color and flavor of meat.

The Philosophical Divide: Utilitarianism vs. Absolutism

The Impossible Burger's controversy highlights a significant philosophical divide within the vegan movement itself. Should one focus on strict adherence to a principle of no animal exploitation (absolutism), or support actions that lead to the greatest good for the greatest number of animals, even if it involves a small amount of harm (utilitarianism)?

Comparison of Vegan Perspectives


Aspect	Utilitarian Vegan Perspective	Absolutist Vegan Perspective
Core Ethical View	Focuses on minimizing net animal suffering. Argues the animal testing was a necessary evil to save far more animals through market disruption.	Focuses on avoiding all forms of animal exploitation. Argues that any animal testing, no matter how limited, makes a product non-vegan.
Stance on Impossible Foods	Sees the company as a positive force, providing a more accessible option for meat-eaters to reduce their consumption, ultimately leading to a net benefit for animals.	Views the company's actions as a betrayal of vegan values. Believes alternative brands that did not test on animals should be supported instead.
Practical Action	May choose to consume the Impossible Burger, recognizing it was made with a vegan end-goal, and seeing it as a step towards a more plant-based future.	Will not consume or financially support the Impossible Burger. Emphasizes finding alternatives that have never been associated with animal testing.
Market Impact	Praises the product's mainstream success, pointing to its ability to reach non-vegans and reduce overall meat demand.	Questions the company's ethics and argues that supporting them sends the wrong message to the industry, prioritizing profit over principles.

Beyond the Patty: The Final Verdict

Ultimately, whether the Impossible Burger is considered vegan depends on an individual's personal interpretation of the term. For many, the plant-based nature of its final ingredients is sufficient. For purists and those who adhere strictly to the principle of zero animal exploitation, the history of animal testing makes it unequivocally non-vegan. There is no single, universally accepted verdict.

The Importance of Context

It's important to remember that the context of consumption matters. For a committed vegan, the animal testing history is a critical factor. For a meat-eater exploring plant-based options for environmental or health reasons, the Impossible Burger offers a highly realistic, animal-free substitute. The conversation around the Impossible Burger serves as a powerful reminder of the complexities and nuanced ethical considerations that exist within the movement for animal rights and plant-based diets.

Conclusion

While all the final ingredients of the Impossible Burger are derived from plants, its approval required a single, controversial round of animal testing on its heme ingredient. This has created a lasting ethical debate, polarizing vegans into those who accept it for the greater good of reducing meat consumption and those who reject it based on the principle of non-exploitation. The ultimate decision rests with the consumer and their personal ethical framework. The Impossible Burger remains a powerful and disruptive force in the food industry, but its status as a truly vegan product is not without its asterisk.

Frequently Asked Questions

The Impossible Burger is controversial among some vegans because its key ingredient, soy leghemoglobin, was tested on rats during its development to gain FDA safety approval.

Yes, all ingredients in the finished Impossible Burger are plant-based. The controversy surrounds the animal testing required for the 'heme' ingredient, not the ingredients in the patty you purchase today.

Heme is an iron-containing molecule that gives meat its characteristic flavor and color. Impossible Foods produces a plant-based version, soy leghemoglobin, by genetically engineering yeast and using a fermentation process.

While the FDA does not require animal testing for food additives, Impossible Foods chose to conduct the tests to speed up the process of receiving a 'no questions' letter for their novel heme ingredient.

Some vegans, following a utilitarian view, support the product because its success helps reduce overall animal suffering by converting meat-eaters. Others, holding an absolutist view, reject it entirely due to the inherent animal exploitation in its testing.

The key difference is that the Beyond Burger did not undergo animal testing to receive regulatory approval, making it a more clear-cut 'vegan' product from an ethical standpoint for many.

Yes, but you should always check. For instance, an Impossible Whopper from Burger King can be made vegan by requesting no mayonnaise, but cross-contamination with meat cooked on the same grill may be a concern for some strict vegans.

No. The animal testing was a one-time event conducted years ago. However, some argue that purchasing the product still financially supports a company with a history of animal testing.