Animal contents in medicines

Our guidance, key principles on avoiding ingredients in medicines discusses factors impacting the choice of an active ingredient or excipient in a medicine. 

When considering if a medicine contains animal derived contents consider both the active ingredient and the excipients (inactive ingredients) present.

Patients may wish to avoid products containing certain animal products or all animal products for one or more reasons relating to:

• cultural factors
• religious factors
• lifestyle factors

The examples provided are not a comprehensive list of all examples of animal contents in medicines.

Active ingredients

Some active ingredients may be derived from animal sources.

Examples include:

• heparins – derived from porcine (pig)
• conjugated oestrogens – contains equine (horse) hormones
• some insulins – derived from bovine (cow) or porcine (pig)
• some MMR and nasal influenza vaccines – derived from porcine or bovine
• some vitamin A and D – derived from cod liver (fish)

Excipients (inactive ingredients)

Excipients are substances other than the active ingredient (drug) that make up a medicine. Some excipients may be derived from animals.

Examples include:

• lactose – derived from milk
• lanolin – derived from sheepskin or wool
• magnesium stearate – derived from plants or bovine tallow
• carminic acid – this is used as a dye in pharmaceuticals and is extracted from cochineal insects
• gelatin – commonly used as a binder in many capsules, it is derived from the skin or ones of pigs, cows or fish
• shellac – this is used as a coating agent and is from the secretions of the female lac insect
• stearic acid – this is used as a lubricant in tablets and capsules, it is often derived from the fats of cows, pigs or sheep

Checking for animal content in medicines

Our guidance on searching for presence or absence of an excipient in medicines provides support on how to find a medicine that is free from a specific excipient.

Use the step-by-step guide and animal content of medicines information included in this article to identify products free from animal-derived content.

It may not be obvious from the product information which active ingredient or excipients are animal-derived. We recommend reviewing the entire document as information on animal-derived content may appear in different sections of the product information.

Sometimes, pharmaceutical companies cannot guarantee or specify the exact sources of animal-derived ingredients. Various suppliers are used in the manufacturing process and the source of ingredients can change. The manufacturer can be contacted for information regarding the suitability of the product for an individual wishing to avoid specific animal content.

The Vegan Society and some SPS resources provide guidance on prescribing for vegetarians and vegans. The information can be used to support queries about avoiding animal content in medicines.

• Choosing calcium and vitamin D products for vegetarians or vegans
• Choosing vitamin D products for vegetarians or vegans

Considerations for specific groups

There are lots of different reasons why people may wish to avoid specific content in medicine.

We provide some general advice about specific patient groups, but this is not comprehensive and values and beliefs may vary between groups. Follow our guidance on key principles on avoiding ingredients in medicines. This article provides further information on how to support these patients.

Our guidance understanding excipients in medicines explains why some people need to avoid particular excipients. Recognising that some patients may refuse animal-derived medications due to cultural or religious beliefs.

Acceptability of animal-derived ingredients will vary between individuals, as alternative diets may be followed for various reasons, with differing moral and ethical beliefs.

Hindu patients

In Hinduism, cattle are considered sacred and it is considered a sin to kill them. Therefore, the use of bovine-derived drugs may not be suitable to patients belonging to Hindu communities.

Jehovah’s Witness patients

Jehovah’s Witnesses believe that the Bible prohibits the consumption, storage and transfusion of blood and its associated products.

Some minor components of plasma (such as, albumin, cryoprecipitate or immunoglobulins) and various clotting factors are not completely forbidden and may be acceptable to some individuals.

Muslim patients

Non-halal medicines may be acceptable, if no alternatives exist.

Muslim patients may also wish to avoid other constituents derived from animals that may not be slaughtered in accordance with Shariah Law.

Porcine (pork) derived products are usually avoided by practising Muslims.

The presence of porcine gelatin in medicines, is a contentious issue, but maybe acceptable to some.

Vegan patients

Vegan diets exercise substances of animal origin, including insects.

Vegetarian diets exclude substances that require the death of an animal or insect.

Substances from live animals are generally acceptable, such as:

• milk and dairy products
• eggs
• honey, beeswax or propolis
• wool fat (lanolin) from living sheep that will not be slaughtered

For further details, see the formal definitions of vegan and vegetarian diets from The European Vegetarian Union.

The Vegan Society advice on medicines recognises that it is not always possible or practicable to avoid the use of animal-derived ingredients. Therefore, the society recommends that individuals follow a vegan lifestyle as far as possible and practicable, enabling them to better look after their health. This will enable individuals to be effective advocates for veganism.

Further information around applying these considerations is discussed within our guidance, key principles on avoiding ingredients in medicines. 

Selecting a suitable alternative

A practical approach for most patients wishing to avoid animal contents in medicines may be to prescribe a vegan suitable medicine if one exists.  

If no suitable alternative from another manufacturer is available and the original medicine is deemed unsuitable after discussion, consider the following alternative options:

• a different strength
• a different formulation (for example, a tablet instead of a capsule)
• a different medicine from the same class
• a different route of administration (for example, patch rather than tablet)
• a medicine from a different class

Any alternative medicine proposed should be safe, clinically effective and cost-effective.

Limitations of our guidance

This article does not cover the use of animals in drug development or the ethics of animal testing.