Chinese hamster ovary cells in medicines

This resource will help you understand how Chinese hamster ovary (CHO) cells are used in medicines, the concerns around its use in medicines for the Muslim community, and whether its use in medicines is halāl (permissible) or harām (prohibited) in Islam. It supports person-centred and informed decision-making around taking medicines that align with an individual’s Islamic values and beliefs.

This resource is for the Muslim community (including patients, carers, parents and members of the public). All healthcare professionals (HCPs), their teams and anyone involved in delivering care and support (across all care settings) to Muslims, may also find it useful.

Table Of Contents
  1. CHO cells
  2. How CHO cells are used in medicines
  3. How medicines are made using CHO cells5
  4. Why this is important
  5. Checking medicine information
  6. Are CHO cells halāl or harām?
  7. What is istihāla (transformation)?
  8. Halāl alternatives
  9. Summary
  10. References and further reading

CHO cells

CHO cells are derived from the epithelial cell line of the ovaries of the Chinese hamster. The Chinese hamster is a small rodent native to China and Mongolia.1Derived from cochil beetles

Chinese hamster

How CHO cells are used in medicines

Due to their similarity to the human cell system, CHO cells are used to make therapeutic proteins in medicines such as biologics (also known as a biopharmaceuticals/biologicals/ group 2) and vaccines (group 3).2 Biologics are used to treat severe inflammatory diseases, autoimmune diseases, and some cancers.2 Biologics are made from living cells and include recombinant proteins, monoclonal antibodies, human growth hormones, cytokines, clotting factors.3

Diagram modified from (Silpa, Bertilla, & Rupachandra, 2023)4

How medicines are made using CHO cells5

CHO cells are not used as an ingredient or excipient but they are used as host cells in the production of biologics and vaccines. The therapeutic proteins needed for biologics and vaccines are produced in the CHO host cells. Genes  are inserted into the CHO cells and instruct them on how to make the protein. The protein is then extracted from the CHO cell and purified to make the medicine (biologics and vaccines). 

Diagram modified from (Carrara et al. 2021)5

Why this is important

For the Muslim community

For the Muslim community, it is important to check if your medicine is made using CHO cells and if it is Islamically permissible to take. To find out if a medicine is made using CHO cells, see the section on ‘Checking medicine information’.

CHO cells are derived from the epithelial cell line of the ovaries of the Chinese hamster. Animals such as hamsters are rodents, which are harām to consume. For further information on the permissibility of CHO cells, see the section on ‘Are CHO cells halāl or harām?‘

For HCPs

For HCPs and anyone involved in delivering care and support, it is important to:

  • Understand which ingredients and/or excipients in medicines may be a concern for practising Muslims and why – for further information, see our resources under ‘Ingredients and excipients in medicines‘
  • Have open discussions with individuals about their personal values or beliefs that may relate to their care and support where possible – e.g. some individuals may wish to avoid certain ingredients/excipients in medicines due to religious beliefs, others may not be as practising or have the same beliefs, so it is important to ask
  • Discuss ideas, concerns and expectations – e.g. during consultations, you may be asked to help individuals to understand whether certain ingredients/excipients are present in their medicine(s), its source, and whether it is likely to be considered permissible in Islam/suitable for a halāl diet
    • To find out how to check if a medicine contains harām ingredients and/or excipients, see section on ‘Checking medicine information’.
    • For further information on the conditions of when it is acceptable for a practising Muslim individual to take/use a medicine that contains harām ingredients and/or excipients, is derived from harām sources, or where there is cross-contamination with harām sources, see our resource on ‘What to do if a medicine contains harām ingredients and/or excipients’
  • Respect and support individuals in making informed decisions about their treatment
  • Understand that you may be asked to explore alternative formulations that meet the individual’s religious requirements (where available), alternative companies that make the medicine without a particular excipient/ingredient (where possible) or alternative treatment options for the condition (where clinically appropriate)
Please take/use your medicine(s) as directed/prescribed by your healthcare professional. 

If you are seeking information about halāl status or alternatives, do not stop, delay, change, or change the way you take/use your medicine(s) without discussing this first with the healthcare professional who prescribed/supplied it to you. 

Always consult your healthcare professional if you have any questions and before making any decisions about your treatment

Checking medicine information

You can check if a medicine was made using CHO cells using the relevant product patient information leaflet (PIL) or summary of product characteristics (SPC) which is available on the electronic medicines compendium (emc) website. CHO is not an ingredient or excipient, therefore information on CHO use may not be listed in the PIL. However, this information is usually available in the SPC under the section on ‘Qualitative and quantitative composition’ instead of ‘List of excipients’. You may also find our resource on ‘How to find out if a medicine contains harām ingredients and/or excipients’ useful. If you are still unsure if your medicine was made using CHO cells, speak to your local pharmacist as they are the experts in medicines.

Examples of common biologic medicines that are derived from CHO cells:6

Please note, this list is not exhaustive, and does not include vaccines. 

Drug NameWhat the drug is used to treat
Avelumabused to treat a variety of cancers
Nivolumab
Pembrolizumab
Abataceptvarious forms of arthritis
Adalimumabusually used to treat rheumatoid arthritis, psoriatic arthritis, plaque psoriasis, Crohn’s disease, uveitis, ulcerative colitis, ankylosing spondylitis and Hidradenitis Suppurativa
Afliberceptvarious disorders of the eyes
Agalsidase betaFabry disease
Darbepoetin alfaanaemia caused by chronic kidney disease
Epoetin alfaanaemia caused by chronic kidney disease, chemotherapy or in those undergoing surgery
Etanerceptusually used to treat rheumatoid arthritis or psoriatic arthritis
Follitropin alfaused to treat infertility in women
Interferon beta-1amultiple sclerosis
Laronidaseused to treat a genetic disorder called Mucopolysaccharidosis type I (MPS I)
Omalizumabused to treat severe allergies, allergic eczema, and certain types of urticaria
Tenecteplasetreats conditions caused by blood clots
Thyrotropin alfaused to treat thyroid cancer

These medicines are usually specialist medicines initiated by specialists. 7


It is important to remember that even if you find out a medicine contains possible harām ingredients and/or excipients, is derived from harām sources, or that there is cross-contamination with harām sources, this does not always mean it is prohibited to take/use. For further information, see our resource on ‘What to do if a medicine contains harām ingredients and/or excipients’. It includes the conditions of when it is acceptable to take/use a medicine in these circumstances. It can also be used to support person-centred discussions between individuals and HCPs, and help make informed decisions around taking medicines that are both clinically appropriate and align with an individual’s Islamic values and beliefs.

Are CHO cells halāl or harām?

The table below summarises the ruling of CHO cells according to the four Sunni schools8:

SourceḤanafīMālikīShāfiʿīḤanbalī
CHO cells❌Harām to consume

The majority of Islamic scholars generally agree that vaccines produced using cell lines from harām animals are impermissible in Islam. The ruling is based on the principle that anything derived from a harām source remains harām, or any material from a legally impure (najis) source remains legally impure (najis), unless a complete and accepted transformation (istiḥāla) occurs.

Istiḥāla is the complete chemical transformation of a legally impure (najis) substance into a completely new substance that is considered legally pure (ṭāhir). For further information on transformation, see section on ‘What is istihāla (transformation)?’. In this case, istiḥāla does not take place. Even though the CHO cells are filtered and removed in later stages of the medicine production process, cell culture methods in vaccine production do not alter the essential properties of the CHO cells (i.e. transformation (istiḥāla) does not occur) and they remain legally impure (najis) and impermissible. There has still been cross-contamination with the legally impure (najis) source regardless of filtration.

If you are still unsure if a medicine is permissible to take, speak to your local Imam or trusted Islamic scholar (ideally who has relevant knowledge and expertise in the Fiqh of medicines).

A note on permissibility

It is important to highlight that many of the medications containing CHO cells lack readily available, equally or more effective halāl alternatives. Consequently, in most instances, their use would likely be considered permissible.

What is istihāla (transformation)?

Istihāla

Istihāla is the complete chemical transformation of a legally impure (najis) substance into a completely new substance that is considered legally pure (ṭāhir). The latter substance no longer retains the chemical properties of its former state (i.e. there has been a change of the original in form, colour, smell, taste, nature, effect, name, use, properties and is irreversible). The substance can undergo this chemical change through scientific or natural means.9 An example of istihāla includes turning wine into vinegar.10

For more detailed information on istihāla, see our e-book on ‘Islamic rulings on the halāl and harām in medicine and food’.

Please note that manufacturers may not be able to provide sufficient information needed for Islamic scholars to determine if istihāla (transformation) has occurred. We would recommend you speak to your trusted Islamic scholar to see if they already have an opinion or criteria on the matter of istihāla.

Halāl alternatives

It is important to note that medicines that use CHO cells are usually specialist medicines, and often there are no halāl alternatives available.

You should seek further advice from your healthcare professional if you are taking these types of medicines.

Summary

  • CHO cells are derived from the epithelial cell line of the ovaries of the Chinese hamster. They are used as host cells to make specialist medicines such as vaccines and biologics (also known as a biopharmaceuticals or biologicals)
  • For the Muslim community, it is important to check if their medicine is produced using CHO cells, and if it is Islamically permissible to take
    • You can check if a medicine was manufactured using CHO cells using the PIL or SPC, alternatively you can speak to your local pharmacist. If you are seeking information about halāl status or alternatives – do not stop, delay, change, or change the way you take your medicine(s) without discussing this first with the healthcare professional who prescribed/supplied it to you
    • Always consult your healthcare professional if you have any questions and before making any decisions about your treatment.
  • For HCPs and anyone involved in delivering care and support to the Muslim community, it is important to have open discussions with individuals about their personal values or beliefs that may relate to their care and support where possible
  • CHO cells are harām because they are derived from a harām source (hamsters are rodents)
    • Follow the guidance of your school of thought (madhhab). If you have further queries about the permissibility of medicines, consult a qualified local Imam or trusted Islamic scholar (ideally someone who has relevant knowledge and expertise in the Fiqh of medicines)
  • CHO cells are usually specialist medicines, and often there are no halāl alternatives available. You should seek further advice from your healthcare professional if you are taking these types of medicines.
  • If you are unsure if your medicine is permissible to take, then speak to your local Imam or trusted Islamic scholar (ideally who has relevant knowledge and expertise in the Fiqh of medicines).

References and further reading

  1. Evitria CHO cells – 7 facts about the cell line derived from the ovary of the Chinese hamster. Accessed 14.3.2025 from: https://www.evitria.com/journal/cho-cells/cho-cells/#:~:text=As%20the%20name%20suggests%2C%20Chinese,toxicity%20assays%20and%20gene%20expression. ↩︎
  2.  Luther, E. (2025) Biological treatments, DermNet®. Available at: https://dermnetnz.org/topics/biologics (Accessed: 10 June 2025) ↩︎
  3. Glinšek, K., Bozovičar, K., & Bratkovič, T. (2023). CRISPR Technologies in Chinese Hamster Ovary Cell Line Engineering. International journal of molecular sciences, 24(9), 8144. Accessed: 10 June 2025. Available at: https://doi.org/10.3390/ijms24098144 ↩︎
  4. Silpa S, Bertilla XJ, Rupachandra S. Emerging trends, challenges, and opportunities in protein therapeutics. In: Singh DB, Tripathi T, eds. Protein-Based Therapeutics. Singapore: Springer; 2023. doi:10.1007/978-981-19-8249-1_11 ↩︎
  5. Carrara SC, Ulitzka M, Grzeschik J, Kornmann H, Hock B, Kolmar H. From cell line development to the formulated drug product: the art of manufacturing therapeutic monoclonal antibodies. Int J Pharm. 2021;594:120164. doi:10.1016/j.ijpharm.2020.120164 ↩︎
  6.  Isu S, Qian X, Zydney A, Wickramasinghe R. Process- and product-related foulants in virus filtration. Bioengineering. 2022;9(4):155. doi:10.3390/bioengineering9040155.   ↩︎
  7.  British National Formulary (BNF). Available at: https://bnf.nice.org.uk/ ↩︎
  8. Islamic use of Hamster Ovary by Shaykh Dr Rafaqat Rashid  ↩︎
  9. Siddiqi, Nasrullah. (2020). Comparative Study of Istihalah Shariah and Chemical Changes. WHS 2020. 89-94. Accessed 27.1.2025 from: https://www.researchgate.net/publication/354339446_Comparative_Study_of_Istihalah_Shariah_And_Chemical_Changes  ↩︎
  10. Jamaludin, Mohammad & Ramli, Mohd Anuar & Hashim, D.M. & Ab Rahman, Suhaimi. (2012). Fiqh Istihalah: Integration of Science and Islamic Law. Revelation and Science. 2. 49-55. Accessed 27.1.2025 from: https://pmc.ncbi.nlm.nih.gov/articles/PMC2014957/ ↩︎

Scroll to Top