This text is for education only. It does not replace advice from a doctor or pharmacist. A doctor decides about treatment, doses and the use of any products. A pharmacist can also give you information.
Many people do not tell their doctor about the supplements they take, because they do not think they need to mention them. Before a visit, people write their medicines on the form, but they see a product from a drugstore as part of their diet. However, this information is important when a doctor assesses your health. Below, we explain where this difference comes from and what is worth mentioning during a visit.
Food supplements and medicinal products – the legal difference
A food supplement is a food and falls under food law. A medicinal product falls under pharmaceutical law. This difference decides how a product is placed on the market, what evidence is needed and how its properties can be described.
| Criterion | Food supplement | Medicinal product |
|---|---|---|
| Category | Food | Medicinal product |
| Legal basis | Food law | Pharmaceutical law |
| Placing on the market | Notification to the competent authority | Marketing authorisation |
| Description of properties | Only claims permitted by law | Indications from the registration documents |
| Responsibility | The business that places the product on the market | The marketing authorisation holder |
A different way of placing products on the market
Before a food supplement is placed on the market for the first time, the business notifies the competent authority. The business that places the product on the market is responsible for its safety and for making sure that it meets the law.
More: How food supplements are supervised in Poland – notification, GIS and producer obligations
A medicinal product needs an authorisation. The authority gives it after it assesses documents on quality, safety and efficacy. This procedure is much more complex.
Different requirements for evidence
For a medicinal product, the indications and doses come from the registration documents. For a supplement, communication is limited to claims permitted by law, and it is not allowed to say that it has medicinal properties.
More: Why a supplement producer cannot promise treatment – health claims in practice
This does not mean that a supplement is an inert product. However, what we know about it is often different from what we know about a medicine.
Why a supplement can matter during treatment
Substances that you take by mouth go through the same metabolic pathways. When you use different products at the same time, this can affect how much of the active substance reaches the bloodstream and how long it stays there.
Below, we describe general mechanisms. We do not name specific pairs of substances and medicines on purpose. To assess such a combination, you need to know the full list of products and the health situation of the person. A doctor or pharmacist makes this assessment.
Effect on absorption
The first mechanism is about what happens in the digestive tract before a substance enters the blood. Changes in stomach pH can matter, because some substances dissolve differently in an acidic environment.
The second effect is when substances bind to each other inside the digestive tract. The complex that forms can be harder to dissolve.
The third factor is the time that the contents need to pass through the digestive tract. This time affects how long a substance is in contact with the surface where absorption takes place.
Effect on how substances are metabolised
The second area is about changes after absorption, mainly in the liver. Enzyme systems are responsible for these changes. Other substances can increase or reduce the activity of these systems.
The result can go in two directions. Faster changes mean that the body removes a substance more quickly. Slower changes mean that the substance stays in the body for longer and at a higher concentration.
A separate group are proteins that carry substances through cell membranes, and removal through the kidneys.
We describe these mechanisms in a general way. Do not use them to draw conclusions about your own situation. A doctor or pharmacist decides whether an important interaction happens in a specific case.
Who needs to be especially careful
The situations below are not a reason to worry. They are a sign that you should definitely talk to a doctor or pharmacist.
- People who take several medicines at the same time. The more products, the more possible combinations.
- People before a planned procedure. Only the doctor in charge of treatment decides what to stop and when.
- Pregnant and breastfeeding women. These situations need individual advice.
- People with long-term illnesses. For example, kidney, liver or heart disease, and conditions that need ongoing treatment.
- Children. The product must be meant for the child’s age group, and it is worth discussing its use with a doctor.
- People during or after antibiotic treatment. It is worth discussing any products that you take during treatment with a doctor. More: The microbiota after antibiotic treatment – what research says and what to ask your doctor
In none of these situations should you stop a medicine, change its dose or replace it with a supplement on your own. Only a doctor makes decisions about treatment.
The pharmacist as an easy-to-reach source of information
You do not need an appointment or a referral to talk to a pharmacist. At a pharmacy, you can ask about a product before you buy it. This is often the simplest way to check.
A pharmacist has access to information about medicinal products and can tell you if you should discuss the topic with your doctor. It is worth giving the pharmacist the full list of products that you take.
Pharmacies also offer pharmaceutical care services. The Act on the profession of pharmacist lists, for example, pharmaceutical consultations and medication reviews as part of this care. A medication review is an assessment of all the medicines that a person uses. Not every pharmacy offers every service, so it is worth asking at your pharmacy.
How to prepare for a talk with your doctor
A well-prepared list makes the talk shorter and lowers the risk that you forget something important. It is better to write it before the visit.
- Write down everything you take. Prescription and non-prescription medicines, food supplements, herbal products and products that you use from time to time.
- Give the doses and how often you take them. How much and how often, and for liquid products, the portion size.
- Bring the packaging or photos of it. The label shows the ingredients, the amount in a portion and the batch number. More: How to read the ingredients of a food supplement – what to look at beyond the marketing name
- Include products that you do not take regularly. This includes seasonal products and products that you take only when needed.
- Note when you started taking them. The start date can be important for the assessment.
- Ask directly about interactions. It is fine to ask: “Does what I take matter for my treatment?”
If the doctor tells you to stop or change anything, follow the doctor’s advice.
Where to report side effects
You report side effects of medicinal products to the Office for Registration of Medicinal Products, Medical Devices and Biocidal Products or to the marketing authorisation holder. Medical staff or patients can make a report.
For food supplements, you report to the sanitary inspection authority and to the business that places the product on the market. It is worth keeping the packaging with the batch number.
A report does not replace contact with a doctor. If you have worrying symptoms, the first step is still to see a doctor.
Summary
A food supplement and a medicinal product are two different legal categories. They are placed on the market in different ways and need different evidence. However, this does not mean that information about a supplement is not important during treatment.
Substances taken at the same time can affect each other mainly through absorption and metabolism. To assess this, you need the full list of products and knowledge of the person’s health situation.
The simplest way is to mention everything that you take and to ask directly. A pharmacist is easy to reach, and a doctor makes decisions about treatment.
This text is for education only. It does not replace advice from a doctor or pharmacist. For questions about treatment, doses and combining products, contact a doctor or pharmacist.
FAQ
Do I need to tell my doctor about supplements if they are not medicines?
It is worth doing this, because a doctor assesses your health based on the full picture of what you take. The legal category of a product does not decide whether information about it is useful.
Can a supplement replace a medicine?
No. A food supplement is a food and is not used to treat illness. Only a doctor makes decisions about treatment. Do not stop or replace prescribed medicines on your own.
Does a time gap between a medicine and a supplement solve the problem?
This is sometimes done in practice, but it is not a general rule. A doctor or pharmacist decides whether a time gap makes sense and how long it should be.
Where can I check information about a product that I take?
The main source is the label and information from the business responsible for the product. If you are not sure, the simplest way is to ask a pharmacist. For questions about treatment, ask the doctor in charge of your treatment.
Sources
- Directive 2002/46/EC of the European Parliament and of the Council of 10 June 2002 on the approximation of the laws of the Member States relating to food supplements.
- Act of 25 August 2006 on food and nutrition safety (as amended).
- Act of 6 September 2001 – Pharmaceutical Law (as amended).
- Commission Regulation (EU) No 432/2012 of 16 May 2012 establishing a list of permitted health claims made on foods, other than those referring to the reduction of disease risk and to children’s development and health.
- Act of 10 December 2020 on the profession of pharmacist (Article 4(2) – scope of pharmaceutical care, including medication reviews).
- Act of 6 September 2001 – Pharmaceutical Law, Article 36d – reporting adverse reactions to medicinal products.
- Chief Sanitary Inspectorate (GIS), Register of products covered by the notification of first placing on the market, https://powiadomienia.gis.gov.pl