Glucosamine is one of the most popular supplements for joint health. Many people take it daily for knee pain, stiffness, or general wear and tear on joints. After eight years as a supplement retailer, I’ve seen how well it can work when used correctly. I’ve also seen confusion around what should or should not be taken with it.
This article answers a common question I hear from customers. What supplements should not be taken with glucosamine?
Let’s keep it simple and practical.
A quick note from experience
In our store, we often suggest glucosamine alongside Nutrivity’s Cod Liver Oil. This recommendation comes from years of customer feedback and repeat buyers who report better joint comfort when the two are used together. That said, not every supplement pairs well with glucosamine. Some combinations need caution.
Below are the main ones to watch out for.
Supplements to Be Careful With When Taking Glucosamine
1. Blood thinning supplements
Glucosamine may have a mild blood thinning effect in some people. On its own, this is usually not an issue. Problems can arise when it’s combined with other supplements that also affect blood clotting.
Be cautious if you take glucosamine with:
- Ginkgo biloba
- Garlic supplements
- Ginger supplements in high doses
- Turmeric or curcumin supplements
- Fish oil in very high doses
This does not mean these supplements are bad. It simply means stacking too many blood thinning supplements together may increase the risk of bruising or bleeding, especially for people who are sensitive.
If you are using cod liver oil or fish oil, moderate doses are generally well tolerated. Many of our customers take glucosamine with cod liver oil without issues. Problems usually show up with excessive dosing or multiple blood thinning products at once.
2. High dose vitamin K antagonists
Vitamin K itself is not harmful. In fact, it plays a key role in bone health. The concern is with supplements that strongly affect blood clotting balance when combined with glucosamine.
If you are taking specialized vitamin K formulas aimed at altering clotting, it’s best to space them out and avoid stacking them without guidance.
For most standard multivitamins, this is not an issue.
3. Shellfish based supplements
Most glucosamine is derived from shellfish. If someone has a shellfish allergy, combining glucosamine with other shellfish based supplements can raise the risk of reactions.
These may include:
- Chitosan
- Certain calcium products made from shellfish
- Marine sourced collagen with shellfish traces
If you or your customers have shellfish sensitivity, always check the source. Plant based or synthetic glucosamine options are available and may be safer.
4. Blood sugar affecting supplements
Glucosamine may slightly affect insulin sensitivity in some people, though this does not happen to everyone. When combined with other supplements that influence blood sugar, the effect may be stronger.
Use caution when stacking glucosamine with:
- High dose chromium
- Bitter melon
- Berberine
- Alpha lipoic acid in large doses
For most healthy adults, this is not a major concern. However, people managing blood sugar levels should monitor how they feel when combining these supplements.
5. Very high dose calcium supplements
Calcium is important for bones, but excessive doses alongside glucosamine may contribute to digestive discomfort in some users. This usually shows up as bloating or constipation.
Spacing calcium and glucosamine at different times of the day often helps.
Supplements That Generally Work Well With Glucosamine
While this article focuses on what to avoid, it helps to mention safe pairings.
Based on customer feedback over the years, glucosamine is often taken successfully with:
- Cod liver oil or fish oil in moderate doses
- Vitamin D
- Vitamin C
- MSM
- Collagen peptides
These combinations are common in joint support routines and are usually well tolerated.
Simple Do’s and Don’ts
Do
- Stick to recommended doses
- Introduce new supplements one at a time
- Read labels carefully
- Listen to your body
Don’t
- Stack multiple blood thinning supplements without thought
- Assume more is always better
- Ignore allergies or sensitivities
- Mix many new supplements at once
Final thoughts
Glucosamine is generally safe and well tolerated, especially when used consistently and sensibly. Most issues come from over stacking supplements or taking very high doses without a clear plan.
After years in supplement retail, I’ve learned that simple routines work best. Glucosamine paired with a quality cod liver oil, like Nutrivity’s Cod Liver Oil, is a combination many customers come back for. Still, every person is different.
Disclaimer
This article is for informational purposes only and is based on retail experience and customer feedback. It is not medical advice. Always consult a qualified healthcare professional before starting, stopping, or combining supplements, especially if you have a medical condition or take medication.

