Medications and a Vegan Diet: Recognising Animal-Derived Ingredients and Finding Alternatives

If you live vegan, you read ingredient lists carefully — and in the package leaflet you come across gelatine, lactose, shellac or wool wax. Many medicines contain animal-derived ingredients, and in some even the active ingredient is of animal origin. Often there are equivalent alternatives, sometimes there are not. And there is a second side that is often overlooked: switching to a vegan diet can change how medicines work — for example with blood thinners, antibiotics or diabetes medicines. This guide shows you both sides and is honest about where the limits lie.

1. Why medicines are rarely “vegan”

Animal-derived substances can be found in three places in a medicine:

• In the excipients: for example gelatine in capsules, lactose as a filler or shellac in the coating. This is the most common case — and the one where alternatives are most likely to exist.
• In the active ingredient itself: for example with heparin or pancreatic enzymes. Here, alternatives are rarer and always a medical question.
• In manufacturing and development: animal-derived components in culture media and, above all, animal testing, which has so far, as a rule, been mandatory for the approval of new active ingredients.

The package leaflet must list all ingredients, but the excipients only “by type” — for example “gelatine” or “magnesium stearate”, but not whether they come from cattle, pigs or plants.^¹ There is no legally regulated vegan label for medicines. Some manufacturers label products voluntarily, mainly over-the-counter medicines and food supplements.

Important for putting this into perspective: The Vegan Society, which coined the term “vegan”, defines veganism as a way of living that seeks to exclude animal exploitation as far as is possible and practicable.^² Many vegans therefore regard necessary medicines as compatible with their stance — and look specifically for alternatives where they exist.

2. Overview: animal-derived ingredients in medicines

Many of these substances also appear in the European guideline on the safety of animal-derived starting materials in medicines — that guideline is about protection against pathogens, not about ethics, but it shows which excipients can be of animal origin.^³

The biggest practical hurdle is not the list but the information on origin: for magnesium stearate, stearic acid or glycerol, the package leaflet usually does not tell you whether they are of animal or plant origin. The only way to find out is to ask (see section 6).

3. Gelatine capsules: the most common stumbling block

Capsules are traditionally made of gelatine. There are two types:

• Hard capsules — in two parts, filled with powder or tiny beads (pellets). For these, there are now often products with capsule shells made of hypromellose (HPMC) or pullulan, which contain no animal-derived ingredients.
• Soft capsules — in one piece, usually with an oily content, for example for fat-soluble vitamins or some prescription-only active ingredients. They are almost always made of gelatine and glycerol; plant-based alternatives exist but are considerably rarer.

Whether the gelatine comes from cattle or pigs is usually not stated in the package leaflet. This matters not only to vegans and vegetarians but also to anyone who avoids pork gelatine for religious reasons.

The better solution is usually a different product with the same active ingredient: as a tablet instead of a capsule, or as a capsule with a plant-based shell. The pharmacy can search for this in a few minutes.

4. When the active ingredient itself is of animal origin

With some medicines, it is not the shell but the active ingredient that comes from an animal. Here in particular: an alternative is a medical decision, not a shopping question.

Vaccines

Some vaccines contain gelatine as a stabiliser, and many flu vaccines are produced in hens' eggs. For flu vaccination, there are also cell culture-based vaccines, but for many other vaccinations there is no alternative. The ingredients a vaccine contains are listed in its Summary of Product Characteristics; the Paul-Ehrlich-Institut (German federal institute for vaccines and biomedicines) provides information on composition and safety.^⁴ Which vaccinations are recommended for adults is shown in the guide Vaccinations for adults.

5. Animal testing and manufacturing: an honest assessment

Even a product with no animal-derived ingredients at all is not automatically free of animal use. For the approval of new active ingredients, authorities in Europe have so far, as a rule, also required animal testing. Animal-free methods are increasingly being used, and animal testing is supposed to be limited to what is strictly necessary according to the principle of “replace, reduce, refine” — but a medicine that has never come into contact with animal testing is currently the exception.

This is uncomfortable, but important for realistic expectations: anyone who wanted to avoid every form of animal involvement could hardly take any medicine at all. Most vegans therefore draw the line where there is a real choice — with excipients and dosage forms.^²

6. Step by step: how to find a vegan alternative

1. Clarify your priorities. Are you concerned about gelatine, about all animal-derived excipients, or also about animal-derived active ingredients? The more clearly you put this, the more targeted the search can be.
2. Read the package leaflet. Section 6 lists all the other ingredients. Look out for gelatine, lactose, shellac, carmine, beeswax, wool wax and the capsule shell.
3. Ask the pharmacy. They can compare products with the same active ingredient, the same strength and the same dosage form and pick out one with a plant-based capsule or without lactose.
4. Follow up with the manufacturer. Every pharmaceutical company must have a scientific information service.^¹ The company's contact details are in the package leaflet. There you can find out whether the magnesium stearate or glycerol is of plant origin.
5. Talk to your practice. If there is no suitable product with the same active ingredient, a different dosage form or a different active ingredient may be an option. The treating practice decides on this.
6. Clarify the costs. A vegan preference is not a pharmaceutical reason to deviate from your health insurer's discount-contract product. You can, however, choose a different product with the same active ingredient as a preferred medicine (Wunscharzneimittel): you pay for it yourself first and get part of it reimbursed by your health insurer — minus deductions.^⁵ With private prescriptions and over-the-counter medicines, you are free to choose anyway.
7. Note it in your plan. Enter your preference as a note, for example “no gelatine capsules”. That way, a new search is not needed with every prescription.

7. Changed your diet: what can change for your medicines

This part is often overlooked: it is not only medicines that can contain animal-derived ingredients — a vegan diet itself can also influence how medicines work. If you change your diet and take medicines, you should tell your practice.

Vitamin K and blood thinners

Green vegetables such as spinach, kale or broccoli are rich in vitamin K. That is healthy — but it can weaken the effect of vitamin K antagonists such as phenprocoumon.^⁶ If you suddenly eat considerably more of them, you risk a falling INR and therefore weaker protection against thrombosis. What matters is not going without but consistency: similar amounts from week to week and more frequent INR checks during the transition phase. Newer anticoagulants (DOACs) are not affected by vitamin K.

Calcium-rich plant drinks and antibiotics

Many oat, soya or almond drinks are fortified with calcium. Calcium can bind certain active ingredients in the gut and reduce their absorption — for example tetracyclines such as doxycycline, fluoroquinolones such as ciprofloxacin, or bisphosphonates for osteoporosis.^⁶ The same spacing rules that the package leaflet gives for milk and dairy products therefore also apply to fortified plant drinks.

Soya, fibre and thyroid hormones

Soya products, a very high-fibre diet and calcium can reduce the absorption of levothyroxine. If you change your diet, you should consistently keep to the interval between your tablet and breakfast and have your thyroid levels checked after a few weeks. Details are in the guide How to take levothyroxine.

Blood pressure, blood sugar, weight

In many people, a plant-based diet lowers weight, blood pressure, blood sugar and cholesterol — good news, but it needs to be reflected in your treatment. If you take insulin or blood sugar-lowering tablets that can cause hypoglycaemia, you should measure more often during the transition phase. If you take blood pressure medicines and suddenly notice dizziness when standing up, you should mention it. Dose adjustments belong in the hands of your practice — they are not something to do on your own.

8. Supplementing nutrients — and watching out for interactions

For a vegan diet, the German Nutrition Society (DGE) recommends permanent vitamin B12 supplementation and advises paying attention to other critical nutrients such as vitamin D, iodine, iron, calcium, zinc, selenium and omega-3 fatty acids.^⁷ Food supplements are not neutral extras, however — they belong in your medication plan.

• Vitamin B12 — B12 products are, as a rule, produced microbially and are therefore usually vegan. A good supply is doubly important if you also take metformin or long-term stomach acid blockers: both can reduce B12 absorption. Have your level checked regularly.
• Vitamin D — conventional vitamin D3 is usually obtained from wool wax. Vegan alternatives are vitamin D3 from lichen or vitamin D2. Whether and how much you should supplement is covered in the article on vitamin D.
• Iron — iron from plant foods is less well absorbed. Iron supplements do not mix with calcium, thyroid hormones and some antibiotics taken at the same time — keep them apart, and only supplement if a deficiency has been confirmed.
• Iodine and omega-3 — iodine from iodised table salt or supplements, omega-3 from algal oil. If you have a thyroid condition, agree your iodine intake with your practice beforehand.

9. Special groups

• Pregnant and breastfeeding women: nutrient requirements rise, and so do the demands on a vegan diet. Medical support and targeted supplementation are particularly important here — as is the rule of not leaving out prescribed medicines because of animal-derived ingredients.
• Children and teenagers: at this stage, a vegan diet needs particularly careful planning and support from a paediatrician. Children's liquid medicines and capsules often contain gelatine, lactose or carmine — the pharmacy can find alternatives.
• Older people: B12 absorption often declines with age. Combined with a vegan diet, metformin or stomach acid blockers, the risk of a deficiency rises markedly.
• People taking blood thinners or with diabetes: a change of diet should be discussed with the practice beforehand, so that check-ups can be scheduled more closely.
• Religious dietary laws: if you avoid pork gelatine for reasons of faith, proceed exactly as described above. Many faith communities make exceptions for necessary medicines — if in doubt, it is worth talking it through.

10. How brite helps you with a vegan diet and medicines

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