Mobility

Glucosamine

Amino sugar supplement for knee osteoarthritis symptoms, with mixed evidence and modest benefits in some adults.

score

evidence

Caution

risk

Our methodology: How we evaluate supplements and turn the underlying research into a single rating.

Read full methodology

Use with caution

This supplement may interact with medications, medical conditions or sensitive populations. Review safety before use.

Overview

Forms

Safety

Stack

Quick Take

Worth considering for symptomatic knee osteoarthritis, especially with crystalline sulfate; otherwise the payoff is limited.

Glucosamine is an amino sugar naturally present in cartilage and synovial fluid; supplements are usually made from shellfish shells or fermented sources. It provides building blocks for glycosaminoglycans and may modestly reduce cartilage breakdown and joint inflammation. The best evidence is for knee osteoarthritis symptom relief, with some data for slower joint-space narrowing. It is most relevant for adults with symptomatic knee osteoarthritis, especially those using crystalline glucosamine sulfate.

Potential benefits

Reduces knee osteoarthritis symptom

May slow knee joint space narrowing

Protocol

Amount

1500 mg

Frequency

Once daily

When

With food to minimize stomach upset; can be taken any time of day.

Onset Time

8-12 weeks for joint symptom changes; no acute effect.

Who Should Consider

Adults with symptomatic knee osteoarthritis

People looking for a low-cost adjunct for knee pain

Older adults with persistent knee stiffness

Those who cannot tolerate standard OA meds

How It Works

Glucosamine serves as a precursor for glycosaminoglycans and proteoglycans, key cartilage matrix components. It may also dampen cartilage-degrading enzymes and NF-κB signaling, lowering inflammatory mediators such as COX-2 and IL-6 in joint tissue.

Updated 5/19/2026