⚕️ Educational information only — not medical advice. Read the full disclaimer

Supplements for Joint Health: An Evidence-Graded Guide

Joint supplements are a multi-billion-dollar market, and the marketing is usually ahead of the evidence. Some have reasonable trial data behind them, some are disappointing in large trials, and some carry real risks: drug interactions, allergies, and rare liver injury. This page grades the most common joint supplements as Strong, Emerging or Contested. It lists the doses that were actually studied and the safety issues to raise with your doctor or pharmacist before you buy anything.

Important: This page is general educational information, not medical advice, and it is not a recommendation to take any supplement. Supplements can interact with prescription drugs, and doses used in studies are not personal dosing advice. Check every supplement with your doctor or pharmacist before starting it, especially if you take blood thinners, biologics, or other prescription medicines, and never stop a prescribed medication without speaking to the prescribing physician.

Key takeaways

  • Omega-3 fish oil is the most studied supplement for rheumatoid arthritis, but trials show at most a small benefit (mainly less NSAID use) at relatively high doses. Emerging (RA, small effect)
  • Curcumin and boswellia show promising pain reductions in knee osteoarthritis, but the trials are mostly small and short. Emerging
  • Glucosamine and chondroitin did not beat placebo overall in the large NIH GAIT trial, and the ACR recommends against glucosamine. Contested
  • Vitamin D should be tested and corrected if low, but extra vitamin D did not slow knee OA in trials. Strong (correct deficiency) Contested (OA benefit)
  • Safety matters more than marketing: vitamin K2 directly opposes warfarin, turmeric and green tea extracts have been linked to liver injury, and high-dose fish oil raises the risk of atrial fibrillation. Strong Glucosamine and turmeric have case reports of raised INR with warfarin. Emerging
  • Choose products with USP or NSF third-party certification, which confirms what is in the bottle. It does not prove that the product works.

How to read the grades

The grades on this page describe the quality of the human evidence for a specific use. They do not describe how popular a supplement is or how plausible its mechanism sounds. A supplement can be Strong for one use and Contested for another. Vitamin D is the clearest example: correcting a deficiency is well supported, but taking more to slow osteoarthritis is not.

Strong

Multiple randomized controlled trials or meta-analyses with consistent results, or a well-established safety fact such as a known drug interaction.

Emerging

Positive but limited evidence: small or short trials, industry-funded studies, animal or lab data, or results that still need independent replication.

Contested

Large or high-quality trials are mixed or negative, or major guidelines recommend against routine use even though some studies were positive.

Most supplement research is in osteoarthritis (OA). Evidence in rheumatoid arthritis (RA) and other inflammatory arthritis is thinner, and none of these supplements replaces disease-modifying treatment for RA. For the prescription side, see arthritis medications.

Comparison table: 14 joint supplements

"Typical studied dose" means the amount used in clinical trials or set as an official reference value. It is not a dosing recommendation. Doses vary by product, formulation and individual, so confirm any dose with your clinician or pharmacist.

Joint supplements at a glance: mechanism, evidence, studied dose and cautions
SupplementProposed mechanismBest evidence forTypical studied doseEvidenceKey interactions / cautions
Omega-3 (EPA/DHA)Shifts eicosanoids away from arachidonic acid; precursor to pro-resolving mediators (SPMs)RA: possible NSAID-sparing; small, uncertain effects on pain and joint counts~2.7–3+ g/day combined EPA+DHA in RA trialsEmerging (RA, small effect) Contested (OA)Atrial fibrillation risk, higher above 1 g/day; bleeding not increased overall in pooled trials, but check if on anticoagulants; fishy reflux; fish allergy
Curcumin / turmericInhibits NF-κB, COX-2 and inflammatory cytokinesKnee OA pain (short-term)~1,000–1,500 mg/day of standard extracts; enhanced-absorption forms at lower doses (e.g., 250–500 mg twice daily)EmergingReported liver injury; anticoagulants (case reports); gallbladder disease; piperine alters drug metabolism
Boswellia serrataBoswellic acids (AKBA) inhibit 5-LOX and leukotrienesKnee OA pain and functionProduct-specific; e.g., 100–250 mg/day of one AKBA-enriched extract (5-Loxin); other extracts used different dosesEmergingGI upset; limited interaction data; avoid in pregnancy
GlucosamineBuilding block for cartilage glycosaminoglycansKnee OA pain: mixed (sulfate vs hydrochloride debate)1,500 mg/dayContestedWarfarin (raised INR reports); usually shellfish-derived; may raise blood sugar in some people
ChondroitinCartilage proteoglycan; may slow matrix breakdownOA pain: mixed; hand OA data more positive800–1,200 mg/dayContestedPossible warfarin interaction (reports mostly with glucosamine combinations); bovine/shark/poultry sources
Collagen: UC-IIUndenatured type II collagen; oral tolerance may dampen immune attack on cartilageKnee OA symptoms (small, mostly industry-funded trials)40 mg/dayEmergingChicken source (egg/poultry allergy); few data
Collagen: hydrolyzed peptidesSupplies amino acids/peptides that may stimulate chondrocytesActivity-related joint pain; OA symptoms10 g/day in the largest trialEmergingBovine/porcine/marine sources; well tolerated
Vitamin DImmune regulation; bone and muscle healthCorrecting deficiency; possible autoimmune-disease prevention (VITAL)Dose to correct a measured deficiency; VITAL used 2,000 IU/dayStrong (deficiency) Contested (OA)Hypercalcemia at excess doses (UL 4,000 IU/day adults); thiazides; test levels first
Vitamin K2 (MK-7)Activates matrix Gla protein, which inhibits cartilage calcificationLow vitamin K status linked with OA (observational)No OA trial of K2; a 3-year vitamin K1 trial showed no overall effect on hand OAEmergingDirectly counteracts warfarin; do not start without prescriber approval
MagnesiumCofactor for vitamin D activation; muscle and nerve functionCorrecting low intake; low magnesium linked with OA (observational)RDA 310–420 mg/day total; supplement UL 350 mg/dayEmergingSeparate from tetracycline/quinolone antibiotics, bisphosphonates; kidney disease; diarrhea
GingerGingerols inhibit COX/LOX pathwaysOA pain (small effect)Product-specific extracts; no standard doseEmergingHeartburn, GI upset; bleeding interaction not well studied
MSMSulfur donor; proposed antioxidant effectsKnee OA pain (small trials)~3.4–6 g/day in knee OA trialsEmergingGI upset; limited long-term safety data
SAMeMethyl donor; proposed cartilage and analgesic effectsOA pain vs NSAIDs (older, small trials)1,200 mg/day in a celecoxib-comparison trialContestedAntidepressants (possible serotonin interaction); bipolar disorder; levodopa; costly
Avocado-soybean unsaturables (ASU)Reduces inflammatory mediators in chondrocytesHip/knee OA symptoms (better in knee)300 mg/dayEmergingSoy/avocado allergy; limited interaction data
Green tea / EGCGPolyphenol antioxidant; inhibits inflammatory signaling (mainly lab data)Mostly preclinical; few human joint trialsNo established dose; concentrated extracts carry riskEmergingLiver injury with concentrated extracts; lowers nadolol levels; caffeine
ProbioticsModulate gut microbiome and immune signaling (gut-joint axis)RA markers in small, strain-specific trialsStrain-specific; no standard doseEmergingCaution if immunosuppressed (biologics, JAK inhibitors, high-dose steroids)

Omega-3 fatty acids (EPA/DHA) Emerging (RA, small effect) Contested (OA)

Marine omega-3s (EPA and DHA from fish or algae oil) are the best-studied supplement for inflammatory arthritis. Individual randomized trials in rheumatoid arthritis have reported reductions in tender joints, morning stiffness or NSAID use, mostly at doses around 3 g/day of combined EPA+DHA, well above typical one-capsule servings.1 Pooled analyses are less encouraging. A 2012 meta-analysis of 10 trials found a clear reduction only in NSAID use (at more than 2.7 g/day for over 3 months), with non-significant trends for joint counts and stiffness.21 A 2024 meta-analysis of 23 placebo-controlled trials found small, statistically uncertain effects on pain, tender and swollen joints, and rated the certainty of evidence low to very low.22 Any effect is small. Fish oil is an add-on and does not replace disease-modifying drugs. In osteoarthritis the evidence is weak, and the ACR/Arthritis Foundation guideline advises against fish oil for OA.11

Mechanism: competing with arachidonic acid

EPA and DHA displace arachidonic acid in cell membranes, so the body makes fewer pro-inflammatory prostaglandins and leukotrienes. They are also precursors for specialized pro-resolving mediators (SPMs), such as resolvins and protectins, which help end an inflammatory response. Food sources are covered in the anti-inflammatory diet.

In the VITAL trial, about 26,000 older U.S. adults took vitamin D (2,000 IU/day), omega-3 (1 g/day) or both.10 During the 5.3-year trial, omega-3 alone did not significantly reduce new autoimmune disease.9 In a follow-up two years after the trial ended, people originally given omega-3 had modestly fewer confirmed autoimmune diseases (hazard ratio 0.83 at 7 years), a finding that still needs replication.25 The vitamin D findings are discussed below. For more, see fish oil for arthritis.

Omega-3 supplements raised the risk of atrial fibrillation in a meta-analysis of large cardiovascular trials (about 25% higher overall, and more at doses above 1 g/day), which matters because RA trials used about 3 g/day.23 Strong (atrial fibrillation) Bleeding is less of a concern than often claimed: a 2024 meta-analysis of 11 trials found no overall increase in bleeding, although high-dose purified EPA raised it slightly.24 People on anticoagulants should still check with their prescriber. Contested (bleeding)

Curcumin / turmeric Emerging

Curcumin is the main active compound in turmeric. Several small randomized trials in knee osteoarthritis report pain relief better than placebo, typically at about 1,000–1,500 mg/day, and a 4-week trial of 367 people found 1,500 mg/day of turmeric extract non-inferior to ibuprofen 1,200 mg/day.2627 Most trials are short, small and use different formulations, and many are industry-funded. NCCIH describes the evidence for turmeric in joint pain as limited.2 See the full turmeric guide for trials, doses and safety.

Mechanism: NF-κB and the bioavailability problem

In lab studies, curcumin inhibits the transcription factor NF-κB, the COX-2 enzyme and cytokines such as TNF-α and IL-6. Curcumin is poorly absorbed, so many products add piperine (black pepper extract) or use nanoparticle, phytosome or micellar forms. These forms raise blood levels, and they may also raise the risk of drug interactions and liver injury.

Liver injury reports: Turmeric used as a cooking spice is generally considered safe. However, cases of liver injury have been reported with turmeric and curcumin supplements, often with high-bioavailability or piperine-containing products.22829 Stop the supplement and contact a clinician promptly if you notice dark urine, yellowing of the skin or eyes, unusual fatigue or upper-abdominal pain. People with liver or gallbladder disease, and people taking anticoagulants or many prescription drugs, should talk to a pharmacist first. Strong (safety signal)

Boswellia serrata Emerging

Boswellia (Indian frankincense) resin extracts are standardized to boswellic acids, especially AKBA. Several randomized trials and meta-analyses report improvements in knee OA pain and function within weeks; a meta-analysis of 7 trials (545 patients) found less pain and stiffness and better function.31 One trial tested 100 or 250 mg/day of an AKBA-enriched extract for 90 days.30 However, many trials test specific proprietary extracts made by the companies funding them, so the results may not apply to other boswellia products. The supplement is usually well tolerated, with mostly GI side effects reported. Interaction data are limited, which means the risks are unknown rather than proven absent.

Mechanism: the 5-LOX pathway

Most anti-inflammatory drugs act on COX. Boswellic acids instead inhibit 5-lipoxygenase (5-LOX), which reduces pro-inflammatory leukotrienes. Lab studies also suggest they reduce cartilage-degrading MMP enzymes.

Glucosamine & chondroitin: the GAIT trial nuance Contested

Glucosamine and chondroitin are the best-known joint supplements and also the most disappointing in rigorous testing. The largest U.S. study, the NIH-funded Glucosamine/chondroitin Arthritis Intervention Trial (GAIT), randomized 1,583 people with knee OA to glucosamine hydrochloride (1,500 mg/day), chondroitin sulfate (1,200 mg/day), both, celecoxib or placebo for 24 weeks.4

1,583Participants with knee OA in GAIT
~60%Placebo response rate, which was high
79% vs 54%Combination vs placebo in moderate-to-severe pain subgroup (exploratory)

What GAIT found: overall, none of the supplement arms reduced pain significantly more than placebo. The placebo response was high, at about 60%. In a smaller subgroup with moderate-to-severe pain, the combination appeared to help: 79% responded, compared with 54% on placebo. That subgroup was small and the analysis was exploratory, so it suggests a hypothesis rather than proving a benefit.43

Why the debate continues

  • GAIT used glucosamine hydrochloride. Several European trials that reported benefit used prescription crystalline glucosamine sulfate, and some researchers argue the two forms differ.
  • Industry-funded trials have tended to report more positive results than independent trials.
  • Chondroitin data in hand OA are somewhat more favorable.

What guidelines say

  • The 2019 ACR/Arthritis Foundation guideline strongly recommends against glucosamine for knee, hip and hand OA. It also recommends against chondroitin for knee and hip OA and gives it a conditional recommendation for hand OA.11
  • The 2019 OARSI guideline does not recommend glucosamine or chondroitin for disease modification.12
Safety: Glucosamine, alone or with chondroitin, has been associated with increased INR and bleeding in people taking warfarin, including about 20 reports in the FDA's MedWatch database and 21 in the WHO database.332 Most glucosamine is made from shellfish shells, so people with a shellfish allergy should ask a clinician or choose a verified non-shellfish source. Glucosamine may raise blood sugar in some people, so people with diabetes should monitor it,3 and a case report links a glucosamine-chondroitin product to an asthma flare.33 Emerging (warfarin: case and database reports)

Collagen: UC-II vs hydrolyzed Emerging

The word "collagen" on a label can mean two very different products, and they are dosed very differently:

Undenatured type II collagen (UC-II) Emerging

UC-II is a tiny dose (about 40 mg/day) of collagen from chicken sternum cartilage, processed to keep its native structure. It is not meant to act as a building block. The proposed mechanism is oral tolerance: exposing gut immune tissue to type II collagen may train the immune system to tolerate it and dampen the immune response against joint cartilage. A few randomized trials report better knee OA scores, but they are small and mostly funded by manufacturers; the largest (191 people, 180 days) used 40 mg/day.34

Hydrolyzed collagen peptides Emerging

Hydrolyzed collagen is a much larger dose (about 5–10 g/day) of collagen broken into peptides, usually from bovine, porcine or marine sources. The proposal is that absorbed peptides signal chondrocytes to make more matrix and supply amino acids such as glycine and proline. A 24-week trial in athletes using 10 g/day found modest improvements in activity-related joint pain.36 In a meta-analysis of OA trials, collagen products improved total WOMAC and pain VAS scores, but not the WOMAC pain subscale.35 Vitamin C is needed for collagen synthesis, which links this to the nutrient-deficiency model.

Both forms are generally well tolerated. Check the source animal if you have allergies or dietary restrictions.

Vitamin D, vitamin K2 & magnesium

Vitamin D Strong (correct deficiency) Contested (OA benefit) Emerging (autoimmune prevention)

Low vitamin D is common and is worth testing; see biomarkers for 25(OH)D. Correcting a true deficiency is well supported for bone and muscle health.5 Taking extra vitamin D to slow osteoarthritis has not worked. In a two-year randomized trial in people with knee OA and low vitamin D, supplementation did not reduce cartilage loss or knee pain compared with placebo.13

The VITAL trial raised a more interesting possibility. Over about five years, adults taking 2,000 IU/day of vitamin D had roughly 22% fewer confirmed autoimmune diseases, including rheumatoid arthritis, than those on placebo.910 A later follow-up weakened this: once extra cases confirmed afterwards were counted, the in-trial result was no longer statistically significant (hazard ratio 0.85, 95% CI 0.70–1.04), and two years after the trial ended the effect had disappeared (hazard ratio 0.98).25 So vitamin D for autoimmune prevention remains unproven. See vitamin D and arthritis for more. More is not better. The adult upper limit is 4,000 IU/day unless a clinician supervises higher doses, and excess vitamin D can cause dangerous hypercalcemia.5

Vitamin K2 Emerging

Vitamin K activates matrix Gla protein, which helps prevent calcium from depositing in cartilage. The mechanism is explained on the root causes page. Observational studies link low vitamin K status with OA, but supplementation trials are few. In a 3-year trial in 378 older adults, vitamin K1 (phylloquinone) had no overall effect on hand OA on X-ray, although people who corrected an insufficiency may have had less joint space narrowing.637 There are no OA trials of K2 supplements.

Warfarin warning: Vitamin K, including K2 supplements, directly counteracts warfarin (Coumadin) and can make it less effective, which raises clot risk. If you take warfarin, do not start, stop or change vitamin K intake without talking to your prescriber.6 Strong

Magnesium Emerging

Magnesium is needed to convert vitamin D into its active form and for normal muscle and nerve function. Many adults get less than the recommended amount, and observational studies associate low magnesium with OA. There are no trials showing that magnesium supplements treat arthritis.7 Magnesium can bind some antibiotics (tetracyclines, fluoroquinolones) and bisphosphonates, so doses need to be separated. It can build up in people with kidney disease. Supplement doses above 350 mg/day often cause diarrhea.7 Long-term proton-pump inhibitor use can lower magnesium; see medications.

Ginger, MSM, SAMe, ASU, green tea & probiotics

Ginger Emerging

A meta-analysis of 5 trials (593 patients) found a modest reduction in OA pain and disability, but people taking ginger were about twice as likely to stop because of side effects.38 It can cause heartburn and abdominal discomfort.15 Whether it adds to bleeding risk with anticoagulants is not well studied, so ask first.

MSM (methylsulfonylmethane) Emerging

A sulfur compound tested in a few small, short knee-OA trials (about 50 people each, 3.4–6 g/day for 12 weeks) with small improvements in pain or function. Long-term safety data are limited.3940

SAMe Contested

Older, small trials compared it favorably with NSAIDs, including a 1,200 mg/day comparison with celecoxib,4746 but a Cochrane review of placebo-controlled trials judged them low quality and inconclusive and advised against routine use.14 It may interact with antidepressants and other serotonin-raising products, may worsen mania in bipolar disorder, and may reduce the effect of levodopa.45

Avocado-soybean unsaturables Emerging

A 300 mg/day extract. A meta-analysis of four manufacturer-supported trials (664 patients) found modest symptom relief, more convincing in knee than hip OA.41 Effects on cartilage structure are unproven.

Green tea / EGCG Emerging

Anti-inflammatory effects are mostly from lab and animal studies. Drinking green tea is generally safe. Concentrated green tea extracts have been linked to liver injury, including liver failure.1642 In a small study, drinking green tea daily cut blood levels of the beta-blocker nadolol by about 85%.43

Probiotics Emerging

These are related to the gut-joint axis. Small RA trials of specific strains show mixed effects on inflammatory markers. Benefits depend on the strain. Probiotics are generally safe, but rare systemic infections have been reported, so people who are immunosuppressed should ask before using them.844

Safety: drug interactions, allergies & liver injury Strong

"Natural" does not mean safe. People with arthritis often take anticoagulants, NSAIDs, methotrexate, biologics or antidepressants, and several common joint supplements interact with these drugs. Bring the actual bottles to your doctor or pharmacist so they can check each ingredient. Labels for blended "joint formulas" often list five or more active compounds.

Interactions and cautions to raise with your pharmacist
If you take or have…Supplements to discuss firstWhyEvidence
WarfarinGlucosamine (± chondroitin), turmeric/curcuminRaised INR and bleeding in case and pharmacovigilance reports32Emerging
Anticoagulants or antiplatelets (clopidogrel, aspirin)Fish oil, gingerTheoretical additive bleeding risk; pooled fish-oil trials found no overall increase in bleeding24Contested
WarfarinVitamin K2 / K1Directly reverses warfarin's effect, raising clot riskStrong
Regular NSAIDsFish oil, turmeric, gingerNSAIDs already raise GI bleeding risk; combined effects are possibleEmerging
Shellfish allergyGlucosamine (most products)Shellfish-derived; allergic reaction is possibleEmerging
Liver disease, methotrexate, leflunomide or heavy alcohol useConcentrated turmeric/curcumin, green tea extractReported supplement-related liver injury2842; these drugs also need liver monitoringStrong
SSRIs, SNRIs, MAOIs, tramadol, triptansSAMePossible serotonin interaction45Emerging
Biologics, JAK inhibitors, high-dose steroidsProbioticsRare serious infections reported in vulnerable people44Emerging
Atrial fibrillation, palpitations or heart diseaseHigh-dose fish oilHigher atrial fibrillation risk in cardiovascular trials, especially above 1 g/day23Strong
NadololGreen tea (drink or extract)Large fall in nadolol blood levels43Emerging
Kidney diseaseMagnesium, high-dose vitamin DRisk of accumulation and hypercalcemiaStrong
Upcoming surgeryFish oil, turmeric, ginger, high-dose vitamin ESurgeons often ask patients to pause these for bleeding reasons; follow your surgical teamEmerging
Pregnancy or breastfeedingMost herbal products (boswellia, high-dose turmeric, SAMe)Safety not establishedEmerging
Do not use supplements to replace prescribed treatment. In inflammatory arthritis such as RA or psoriatic arthritis, delaying disease-modifying therapy can cause permanent joint damage. Supplements can be discussed as additions, not substitutes, and you should never stop a prescribed medication without speaking to the prescribing physician. See medications for context.

Quality & third-party testing

In the United States, the FDA does not approve dietary supplements for safety or effectiveness before they are sold. Manufacturers are responsible for their own products, and contamination, mislabeled doses and undeclared ingredients do occur. Between 2007 and 2016 the FDA identified 776 supplements containing hidden drug ingredients, mostly products for sexual enhancement, weight loss or muscle building.171848 Independent certification is the best protection consumers have.

Look for

  • The USP Verified mark: checks identity, potency, purity and manufacturing practices.19
  • NSF certification (including NSF Certified for Sport): checks label accuracy and contaminants.20
  • Doses and forms that match those used in trials, such as a standardized extract percentage or combined EPA+DHA per serving rather than total "fish oil".
  • Single-ingredient products, so you know which ingredient is causing a benefit or a side effect.

Be wary of

  • Claims to "cure", "reverse" or "rebuild cartilage".
  • "Proprietary blends" that hide individual doses.
  • Very high-bioavailability botanical products, which have been linked to more liver-injury reports.
  • Products sold mainly through social media, or "doctor-formulated" products without third-party testing.
A practical approach to discuss with your clinician: test first, for example vitamin D and magnesium status (see biomarkers). Try one supplement at a time, at a studied dose, for a defined period (often 8–12 weeks). Track pain and function, and stop if there is no clear benefit. A food-first approach, such as oily fish, turmeric and ginger in cooking, and a Mediterranean pattern, comes with fewer risks; see the anti-inflammatory diet.
Dietary & supplement note: Statements here about nutrients and dietary supplements have not been evaluated by the U.S. Food and Drug Administration (FDA) and are not intended to diagnose, treat, cure, or prevent any disease.

Frequently asked questions

Which supplement has the best evidence for arthritis?

Fish oil (omega-3 EPA and DHA) is the most studied supplement for rheumatoid arthritis, but the benefit is small: an older meta-analysis found mainly reduced NSAID use at doses above about 2.7 g/day, and a 2024 meta-analysis of 23 placebo-controlled trials found only small, uncertain effects on pain and joint counts. Curcumin and boswellia have promising but smaller trials in osteoarthritis. No supplement replaces prescribed treatment. Check any supplement with your doctor or pharmacist first.

Does glucosamine actually work?

The evidence is mixed. In the large NIH-funded GAIT trial (NEJM 2006), glucosamine hydrochloride, chondroitin, or both did not reduce knee osteoarthritis pain significantly more than placebo overall. A smaller subgroup with moderate-to-severe pain appeared to benefit from the combination, but that was exploratory. The American College of Rheumatology recommends against glucosamine for knee, hip, and hand osteoarthritis.

Can turmeric or fish oil interact with blood thinners?

Possibly, so check first. Glucosamine has been linked to a raised INR in people taking warfarin, and turmeric has case reports of the same. For fish oil, a 2024 meta-analysis of 11 large trials found no overall increase in bleeding, although high-dose purified EPA raised it slightly. Ginger's effect is not well studied. Never start or stop these on your own if you take a blood thinner. Ask your prescriber or pharmacist.

Is turmeric safe for the liver?

Turmeric as a cooking spice is generally considered safe, but cases of liver injury have been reported with turmeric and curcumin supplements, particularly concentrated or enhanced-absorption products. Stop the supplement and contact a clinician promptly if you develop dark urine, yellowing skin or eyes, unusual fatigue, or abdominal pain.

How do I choose a quality supplement?

In the United States, dietary supplements are not approved by the FDA for safety or effectiveness before sale. Look for independent third-party certification such as the USP Verified Mark or NSF certification, which check that a product contains what the label says and is not contaminated. Certification does not prove the supplement works.

References

  1. Omega-3 Fatty Acids — Fact Sheet for Health Professionals. NIH Office of Dietary Supplements. ods.od.nih.gov/factsheets/Omega3FattyAcids-HealthProfessional/
  2. Turmeric — National Center for Complementary and Integrative Health (NCCIH). nccih.nih.gov/health/turmeric
  3. Glucosamine and Chondroitin for Osteoarthritis — NCCIH. nccih.nih.gov/health/glucosamine-and-chondroitin-for-osteoarthritis
  4. Clegg DO, Reda DJ, Harris CL, et al. Glucosamine, chondroitin sulfate, and the two in combination for painful knee osteoarthritis (GAIT). New England Journal of Medicine. 2006;354(8):795–808. PubMed 16495392
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  6. Vitamin K — Fact Sheet for Health Professionals. NIH Office of Dietary Supplements. ods.od.nih.gov/factsheets/VitaminK-HealthProfessional/
  7. Magnesium — Fact Sheet for Health Professionals. NIH Office of Dietary Supplements. ods.od.nih.gov/factsheets/Magnesium-HealthProfessional/
  8. Probiotics — Fact Sheet for Health Professionals. NIH Office of Dietary Supplements. ods.od.nih.gov/factsheets/Probiotics-HealthProfessional/
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  11. Kolasinski SL, Neogi T, Hochberg MC, et al. 2019 American College of Rheumatology/Arthritis Foundation Guideline for the Management of Osteoarthritis of the Hand, Hip, and Knee. Arthritis Care & Research. 2020;72(2):149–162. PubMed 31908149
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  14. Rutjes AWS, Nüesch E, Reichenbach S, Jüni P. S-Adenosylmethionine for osteoarthritis of the knee or hip. Cochrane Database of Systematic Reviews. 2009. PubMed 19821403
  15. Ginger — NCCIH. nccih.nih.gov/health/ginger
  16. Green Tea — NCCIH. nccih.nih.gov/health/green-tea
  17. Dietary Supplements — U.S. Food and Drug Administration. fda.gov/food/dietary-supplements
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  19. USP Verified Mark — U.S. Pharmacopeia. usp.org/verification-services/verified-mark
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