Understanding Your Prescriptions: Which Medicines are Not Vegan?

October 31, 2025 •

4 min read

According to a 2013 report, 74 of the 100 most commonly prescribed drugs contained at least one non-vegan excipient like lactose, gelatin, or magnesium stearate. For individuals on a vegan diet, navigating the world of medication can be challenging, as it requires knowing which medicines are not vegan due to animal-derived components hidden in both active and inactive ingredients.

Quick Summary

Many common prescription and over-the-counter medications contain hidden animal-derived ingredients, from gelatin in capsules to lactose used as a filler. Active ingredients like heparin and some forms of insulin also originate from animal sources. Knowing how to identify these non-vegan components and communicate with healthcare professionals is essential for finding suitable alternatives.

Key Points

Hidden Ingredients: Many medications contain animal-derived ingredients like gelatin (capsules) and lactose (fillers) that aren't obvious from the product name.
Animal-Based Active Compounds: Certain vital drugs, such as some blood thinners (heparin) and hormones (conjugated estrogens), are sourced directly from animals.
The Labeling Problem: Pharmaceutical labeling doesn't always specify the source of ingredients like stearic acid or glycerin, which can be either animal- or plant-derived.
Consulting a Pharmacist is Key: The most reliable way to verify a medication's vegan status is to ask a pharmacist or contact the manufacturer directly, as product formulations can change.
Veganism and Medical Necessity: The Vegan Society's definition prioritizes health when essential medication is needed, acknowledging that animal-free options may not always be available.
Available Alternatives: For some medications, especially capsules and vitamin D supplements, plant-based or synthetic alternatives exist and may be available through your doctor or pharmacist.

Common Animal-Derived Ingredients in Medications

Many people are surprised to learn that pharmaceutical products often contain ingredients derived from animals. These can be categorized into active ingredients, which are the therapeutic components, and excipients, which are the inactive substances that help form the medicine and improve its stability or absorption.

Animal-Derived Active Ingredients

Some of the most critical medications on the market are directly sourced from animal products. For vegans, this requires an ethical consideration and a discussion with a healthcare provider to explore potential alternatives.

Heparin: This blood thinner, used to prevent blood clots, is commonly derived from the intestinal mucosa of pigs.
Animal Insulins: While most modern insulins are synthetic, older versions derived from the pancreas of cows (bovine) or pigs (porcine) still exist.
Conjugated Estrogens: Used in hormone therapy, these are extracted from the urine of pregnant mares, as seen in the product Premarin.
Pancreatic Enzymes: Supplements for pancreatic insufficiency, like pancrelipase, are derived from pig pancreases.
Vitamin D3 (Cholecalciferol): Often sourced from lanolin, a fat found in sheep's wool. Vegan versions from lichen or other plants are available, but their origin must be confirmed.
Propofol: This anesthetic commonly contains egg lecithin, derived from purified chicken egg yolks.

Hidden Animal Excipients

Excipients are frequently the cause of a medication being non-vegan and are often less obvious than active ingredients. It is crucial to check the ingredient list or consult a pharmacist to identify them.

Gelatin: A key ingredient in many capsule shells, this is made from the skin, bones, and connective tissue of animals, primarily cows and pigs.
Lactose: Derived from cow's milk, this sugar is a very common filler and binder in tablets.
Stearic Acid and Magnesium Stearate: Used as lubricants in tablet manufacturing, these can be sourced from either animal fats (tallow) or plants. The origin is not always specified on the label.
Shellac: A resin secreted by the female lac insect, used as a coating agent for tablets and to bind powders.
Carmine/Cochineal: A red dye produced from crushed cochineal insects, used for coloring capsules and coatings.
Glycerin: Can be sourced from either animal fat or vegetable oils. Without clear labeling, it can be uncertain.

Checking Your Medication for Animal-Derived Ingredients

Given the lack of standardized labeling, verifying a medication's vegan status is not always straightforward. You must be proactive in your approach, involving your healthcare team and sometimes contacting manufacturers directly.

How to Verify Your Medication

Read the Patient Information Leaflet (PIL): Look inside the medicine box for the leaflet, which contains the list of all ingredients, including excipients. Search for common non-vegan terms like gelatin, lactose, and lanolin.
Consult Your Pharmacist: Pharmacists have access to detailed product information and can often identify the source of ambiguous ingredients like magnesium stearate.
Contact the Manufacturer: For definitive answers, especially concerning ingredients with variable sources, contacting the pharmaceutical company's medical information service is the most reliable method.

Potential Vegan Alternatives and Ethical Considerations

While not all medications have a readily available vegan alternative, advances in manufacturing mean that plant-based options are becoming more common. For instance, manufacturers now produce capsules made from hydroxypropyl methylcellulose (HPMC), a plant-based cellulose. Liquid or dissolvable tablet formulations are also often animal-free, though they can sometimes be more expensive.

Comparison Table: Common Non-Vegan vs. Alternative Sources


Ingredient	Common Non-Vegan Source	Potential Vegan Alternative/Source
Capsules	Gelatin (Bovine, Porcine)	Hydroxypropyl Methylcellulose (HPMC), Pregelatinized Starch
Filler/Binder	Lactose (Cow's Milk)	Mannitol, Sucrose, Cellulose
Lubricant/Coating	Stearic Acid (Animal Tallow)	Stearic Acid (Plant-derived), Cellulose
Vitamin D3	Lanolin (Sheep's Wool)	Vitamin D2 (Ergocalciferol), Lichen-sourced D3
Blood Thinner	Heparin (Porcine Intestine)	Fondaparinux (Synthetic), Other Oral Anticoagulants

The Vegan Society's definition acknowledges that avoiding animal products is not always possible and practicable, particularly in the context of essential medication. It is important to remember that prioritizing your health is essential. Discussions with your doctor should focus on finding the most effective treatment while considering your ethical concerns, not on forgoing necessary medical care.

Conclusion

For those adhering to a vegan lifestyle, understanding which medicines are not vegan due to their ingredients is a critical aspect of holistic health management. By being vigilant about researching active and inactive ingredients and working with healthcare professionals, you can make informed decisions. While challenges remain, especially with older medications or those tested on animals, the pharmaceutical industry is slowly moving towards more transparent and plant-based alternatives. Prioritizing your health with effective medication while advocating for greater transparency remains the most pragmatic approach for any vegan.

To learn more about this topic, visit The Vegan Society's comprehensive blog on vegan-friendly medicines: https://www.vegansociety.com/news/blog/practical-considerations-vegan-friendly-medicines.

Frequently Asked Questions

Gelatin is a protein derived from the skin, bones, and connective tissues of animals, most commonly cows and pigs. It is used to create the hard or soft shells of many capsules, making any medication in gelatin capsules unsuitable for vegans.

Lactose is a sugar derived from cow's milk and is often used as a filler in tablets. While it doesn't pose a health risk to those without lactose intolerance, it is an animal product and therefore not suitable for a vegan diet.

Virtually all pharmaceutical drugs have been tested on animals at some point during their development, although for decades-old drugs, this testing may have occurred long ago. The vegan ethical position acknowledges this challenge and focuses on avoiding animal-derived ingredients where possible and practicable.

No, not for all. While alternatives exist for some common issues (e.g., synthetic insulins, plant-based capsules), some medications, particularly those with animal-derived active ingredients like heparin, may not have an equally effective or readily available vegan alternative.

The best approach is to check the patient information leaflet for ingredients like gelatin, lactose, or carmine, and then consult your pharmacist. For ambiguous ingredients, the manufacturer's medical information service can provide the source.

Pharmaceutical regulations primarily focus on a drug's safety and efficacy, not lifestyle choices like veganism. This lack of regulated labeling for dietary preferences can make identifying animal products challenging for consumers.

You should not stop taking essential medication without professional guidance. The Vegan Society advises that prioritizing your health is paramount. Discuss alternatives with your doctor, but understand that taking the prescribed medication may be necessary for your well-being.

No. Many supplements can contain animal-derived ingredients like gelatin (in softgels), lanolin (for vitamin D3), or fish oil (for omega-3s). Always read the ingredient label carefully and look for third-party vegan certifications.