Medicines, Supplements & “Natural” Remedies
Last episode, we looked at everyday habits that protect your kidneys.
This time, we’re asking a different question — one that matters just as much:
What are you putting into your body?
Because here’s the thing about kidney health that often gets overlooked: your kidneys filter waste from your blood and help remove many medicines and their by-products from your body.
Your liver also plays an important role in processing substances you consume. Certain medicines, supplements and herbal preparations can harm the kidneys, particularly when used incorrectly or by people with existing kidney problems.
The good news is that understanding what you take, and using medicines and supplements appropriately, can help reduce avoidable risks to your kidneys.
Let’s walk through what you need to know.
YOUR KIDNEYS AND MEDICINES: A NECESSARY RELATIONSHIP
Let’s start with an important clarification: medicines are not the enemy.
Many medicines are essential. They control blood pressure, manage diabetes, treat infections, and save lives. For people with kidney disease, some medicines actually protect the kidneys from further damage.
But medicines are also chemicals. And your body has to process and remove them. That means:
- Some medicines can harm the kidneys directly.
- Some medicines need dose adjustment when kidney function is reduced.
- Some combinations of medicines increase risk.
- Some “natural” products contain substances that damage the kidneys.
The goal isn’t to avoid all medicines. It’s to use them thoughtfully.
PAINKILLERS: A COMMON AND PREVENTABLE RISK
If there’s one category of medicine worth understanding, it’s NSAIDs — nonsteroidal anti-inflammatory drugs.
These include familiar names like ibuprofen, naproxen, and diclofenac. They’re commonly used for pain, fever, and inflammation. And they’re often taken without a second thought.
The problem: NSAIDs can reduce blood flow to the kidneys. For most otherwise healthy adults, short-term use at the recommended dose generally carries a low risk of kidney damage.
However, NSAIDs can cause kidney injury, particularly in people who are dehydrated, have certain medical conditions or take medicines that affect kidney function. Frequent or prolonged use increases the risk.
What this means in practice:
- Don’t take NSAIDs routinely for chronic pain without medical advice.
- Avoid NSAIDs when you’re dehydrated, particularly if you have vomiting, diarrhoea or difficulty drinking enough fluids.
- If you have kidney disease, ask your doctor before using them.
- Don’t combine multiple NSAID products.
Paracetamol (acetaminophen) is generally considered safer for the kidneys when taken at recommended doses, though it carries its own risks in overdose.
Check the labels of cold and flu medicines, as some contain paracetamol or NSAIDs. Taking multiple products containing the same ingredient can lead to accidental overdosing. People with liver disease should consult their doctor before taking paracetamol.
If you take medicines for high blood pressure or water pills (diuretics), ask your doctor or pharmacist before using NSAIDs. Certain combinations can increase the risk of kidney injury, particularly when you’re dehydrated.
MEDICINES THAT NEED DOSE ADJUSTMENT
Some medicines are processed and removed by the kidneys. When kidney function is reduced, these medicines can build up in the body — increasing the risk of side effects or toxicity.
This is why your doctor may adjust doses of certain medicines if you have kidney disease. It’s also why telling your healthcare team about your kidney status matters.
Common examples include certain antibiotics, diabetes medicines, and blood thinners. You don’t need to memorize the list — you need to make sure whoever prescribes for you knows your kidney function.
HERBAL REMEDIES AND “NATURAL” PREPARATIONS
This is where the conversation gets particularly important for our context.
In Nigeria — and across much of Africa — herbal preparations are widely used. They’re part of tradition, they’re accessible, and many people trust them. Some have genuine medicinal value.
But here’s what often goes unspoken: “natural” does not mean “safe for your kidneys.”
Some herbal preparations contain substances that are directly toxic to kidney tissue. One example is aristolochic acid, found in certain traditional herbal products.
It can cause severe kidney damage and has also been linked to cancers of the urinary tract. Products containing it are restricted or prohibited in several jurisdictions.
Others contain heavy metals or contaminants. Some interact with prescription medicines. Some herbal products may be unregistered, inadequately tested or inaccurately labelled, making it difficult to know exactly what they contain.
The 2024 KDIGO guideline on kidney disease explicitly lists several herbal products with evidence of kidney toxicity and recommends that healthcare providers ask patients about their use.
This doesn’t mean you should never use traditional remedies. It means:
- Tell your doctor about everything you take — including herbal preparations.
- Be cautious with remedies whose contents you don’t know.
- Avoid preparations marketed as “cures” for kidney disease or diabetes.
- If you’re already taking prescription medicines, check for interactions.
In Nigeria, check whether a herbal product is registered with NAFDAC, and verify its registration number through the agency’s official website.
However, registration does not mean a product is suitable for everyone, particularly people with kidney disease. You should still check the ingredients and consult a qualified healthcare professional before use.
SUPPLEMENTS: NOT AUTOMATICALLY HARMLESS
The supplement industry is enormous, and the messaging is often reassuring. But supplements can affect the kidneys too.
Some concerns include:
- High-dose vitamin C can increase the risk of kidney stones in some people.
- Creatine supplements, commonly used for exercise and muscle performance, may increase blood creatinine levels without necessarily damaging healthy kidneys. Because creatinine is used to estimate kidney function, this can sometimes make test results appear worse than they actually are. Tell your doctor if you use creatine, especially if you have kidney disease or are undergoing kidney function tests.
- Certain weight-loss or bodybuilding supplements have been linked to kidney injury.
- Potassium supplements and potassium-based salt substitutes can be dangerous for people whose kidneys cannot remove excess potassium effectively. Coconut water also contains substantial amounts of potassium, so drinking large quantities may be unsuitable for some people with kidney disease. Ask your healthcare professional whether you need to limit potassium rather than restricting these products unnecessarily.
If you take supplements regularly, mention them to your doctor — especially if you have kidney disease or risk factors.
THE MOST IMPORTANT RULE: TELL YOUR DOCTOR EVERYTHING
This is the single most important takeaway from this episode.
Your healthcare team can only protect you if they know what you’re taking. That includes:
- Prescription medicines
- Over-the-counter painkillers
- Supplements
- Herbal preparations
- Traditional remedies
- Anything else you take regularly
Don’t assume it’s unimportant because it’s “natural” or because you’ve been taking it for years. Don’t assume your doctor will ask. Bring it up.
A NOTE ON SICK DAYS
When you’re vomiting, have diarrhoea or cannot drink enough fluids, dehydration may increase the risk of kidney injury. Some prescribed medicines may need to be temporarily paused during such illnesses.
Ask your doctor or pharmacist to help you prepare a personal sick-day medication plan, including instructions on which medicines to pause and when to restart them.
Follow that plan rather than making medication changes without professional guidance. Seek medical attention if you cannot keep fluids down or develop signs of serious dehydration.
BEFORE YOU TAKE SOMETHING, ASK YOURSELF
Here’s a simple checklist to run through:
- Do I actually need this?
- How often am I taking it?
- Am I taking other medicines that might interact?
- Do I have kidney problems or risk factors?
- Has a healthcare professional advised me to use this?
- Do I know what’s actually in it?
If you can’t answer these confidently, that’s a signal to ask before you take it.
THIS EPISODE’S TAKEAWAY
Your body has to process almost everything you put into it. Medicines can help or harm. Supplements aren’t automatically safe. And “natural” doesn’t mean “kidney-friendly.”
Kidney damage can develop without noticeable symptoms. Feeling healthy does not always mean your kidneys are functioning normally, which is why appropriate testing and regular medical reviews are important, especially if you have risk factors.
The goal isn’t fear. It’s awareness. Use medicines thoughtfully, tell your doctor what you’re taking, and be cautious with anything whose contents you don’t fully know.
Next episode, we’ll look at warning signs — what kidney problems can look like, what they don’t look like, and when to seek help.
A QUICK REFLECTION BEFORE NEXT WEEK
- Do you know what’s in every medicine or supplement you take regularly?
- Have you ever told your doctor about herbal preparations you use?
- Is there anything in your routine that you’ve never questioned?
Bring those questions to Episode 5.
SOURCES FOR FURTHER READING
- KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of CKD Read source
- NIDDK — Keeping Kidneys Safe: Smart Choices About Medicines Read source
- National Kidney Foundation — Pain Medicines (Analgesics) Read source
- National Kidney Foundation — Herbal Supplements and Kidney Disease Read source
- NAFDAC Registration Verification Portal Read source
Editor’s note: This article is for general health education and does not replace personalised medical advice from a qualified healthcare professional.
