Major interaction on record — check this product against your medications before combining. Based on 1 of 7 ingredients. Check your meds →
Dietary supplement

Celadrin & MSM Ingredients & Drug Interactions

by NOW

Celadrin & MSM label
See full label image
Capsule Category: Other Combinations
Most serious interaction: Major
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Celadrin & MSM against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.

Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy

The interaction bottom line Most serious interaction: Major

Celadrin & MSM is a dietary supplement by NOW with 7 active ingredients. Its ingredients are commonly taken for eye and vision health, skin health and acne, immune support.Based on those ingredients, 387 medications have a known interaction with it, the most serious rated major. The ingredients most likely to interact are Vitamin A Palmitate. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Celadrin & MSM by NOW

Ask about any prescription or over-the-counter medication and we check it for interactions with Celadrin & MSM by NOW — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Celadrin & MSM by NOW

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 11, 2026

What’s inside

Low disclosure
Ingredient Transparency · database check
Low

Most active ingredients don't disclose an individual amount — you can't tell how much of each you're getting.

Why this rating?
  • The label discloses an exact amount for 1 of its 7 active ingredients.
  • “Celadrin” is listed as a grouped ingredient — the label gives one combined amount (1.50 Gram(s)) without saying how much of each component you get.

This product has 7 active ingredients. The main one we have interaction data for is vitamin A palmitate, a form of vitamin A.

The other six are MSM (methylsulfonylmethane), Cetyl Myristoleate, Cetyl Myristate, Cetyl Laurate, Cetyl Palmitoleate, and Cetyl Oleate — these are fatty acid compounds collectively part of the Celadrin blend. The capsules also contain inactive ingredients: gelatin, sodium copper chlorophyllin, magnesium stearate, and silica.

Does it work?

Not established
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed
Not established

The graded evidence we hold for these ingredients covers different conditions than the ones this product is marketed for, so there's no established rating for its stated use — see Vitamin A's own graded uses on its monograph.

Why this rating?
  • The label markets this product for: support healthy joints and joint mobility.
  • We looked for evidence on: Osteoarthritis, Joint pain, Joint stiffness, Cartilage health.
  • The closest evidence on file: Vitamin A is rated "Insufficient Reliable Evidence To Rate" for Osteoarthritis (Natural Medicines).

Vitamin A palmitate is effective for vitamin A deficiency and has possibly effective evidence for oral leukoplakia (a precancerous mouth condition), aging skin, measles, ulcerative colitis, and bronchopulmonary dysplasia (a lung condition in premature infants). We don't have effectiveness data on file for the other ingredients in this product.

The evidence, ingredient by ingredient Vitamin A

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 1 of the 1 matched ingredient.
  • Pregnancy & breastfeeding safety ratings cover 1 of 1.
  • General safety write-ups exist for 1 of 1.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Vitamin A is generally well tolerated at recommended doses, but the safety data cautions that high doses are toxic because vitamin A builds up in your body over time. Rare serious effects from very high doses include pseudotumor cerebri, liver toxicity, and neurological symptoms.

Chronic overuse can cause dry, cracking, itchy, or peeling skin, brittle nails, hair loss, and gum problems. For pregnancy and breastfeeding, the data shows vitamin A at recommended amounts is likely safe, but the safety notes also flag that high doses — especially as retinol — can cause birth defects and should be avoided.

Side effects, ingredient by ingredient Vitamin A

Meds to double-check

Major interaction found
Known Interaction Concern · database check
Major identified

At least one ingredient has a documented Major-severity interaction. Check your medications for a personalized result.

Why this rating?
  • 1 of the 1 matched ingredient can interact with medications — Vitamin A.
  • The most serious interaction on file is rated Major.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs.
  • For scale: 388 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

Before you start, double-check if you're on retinoid medications (like tretinoin for acne), warfarin or other blood thinners, tetracycline antibiotics (like doxycycline), or any drug known to stress the liver. These are the medication types where the interactions are documented.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFormula with limited ingredient disclosure with no established evidence rating for its marketed use. Major medication interactions have been identified, and safety information is well characterized.

If you take a retinoid medication, a blood thinner, tetracycline antibiotics, or drugs that stress your liver, check with us or your pharmacist before starting this product. For anyone else, use it at the label dose and don't exceed it — vitamin A toxicity is real when you take too much.

Talk to your pharmacist if you're pregnant, planning pregnancy, or breastfeeding.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 1 of 7 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Mar 24, 2017.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about Celadrin & MSM, straight from the product label.

Brand NOW
Barcode (UPC) 733739030160
Net contents 120 Capsule(s)
Market status On market
Date entered into DSLD Mar 24, 2017
DSLD ID 72474
Product type Other Combinations
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Gluten Free, Dairy Free
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for Celadrin & MSM by NOW, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
3 Capsule(s)
Maximum serving Sizes:
3 Capsule(s)
Servings per container
40
UPC/BARCODE
733739030160
IngredientAmount% DV
Calories15 Calorie(s)--
Total Carbohydrates1 Gram(s)1%
Total Fat1 Gram(s)1%
Vitamin A Palmitate0 NP--
MSM300 mg--
Cetyl Myristoleate0 NP--
Cetyl Myristate0 NP--
Cetyl Laurate0 NP--
Cetyl Palmitoleate0 NP--
Cetyl Oleate0 NP--
Celadrin1.5 Gram(s)--

Other ingredients: Gelatin, Sodium Copper Chlorophyllin, Magnesium Stearate, Silica

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
Suggested/Recommended/Usage/Directions

Suggested Usage: Take 3 capsules daily with food.

Brand IP Statement(s)

Celadrin is a unique natural fatty acid complex that has been shown to help support healthy joints.* Celadrin has been clinically studied for its ability to support healthy joint mobility and overall joint function.* Non-clinical scientific studies have shown that Celadrin is well-absorbed and easily utilized by the body.*

Celadrin is a registered trademark of Imagenetix Corporation.

Formula

For added support, each 3 capsule serving of NOW Celadrin & MSM includes 300 mg of MSM.*

~ 500 mg Celadrin

Celadrin

General Statements

This biologically active sulfur compound supports the formation of both collagen (a key component of cartilage) and sulfur-containing amino acids such as cysteine.*

Capsule size

Advanced joint support*

~ Supports joint mobility*

General Health

Family owned since 1968.

Natural color variation may occur in this product.

Please recycle.

FDA Disclaimer Statement

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.

Precautions

Caution: For adults only.

Consult physician if pregnant/nursing, taking medication, or have a medical condition (especially glaucoma).

Keep out of reach of children.

Do not eat freshness packet. Keep in bottle.

Not manufactured with wheat, gluten, soy, milk, egg, fish, shellfish or tree nut ingredients. Produced in a GMP facility that processes other ingredients containing these allergens.

General

CODE 3016 V4

FDA Statement of Identity

A Dietary Supplement

Formulation

Not manufactured with wheat, gluten, soy, milk, egg, fish, shellfish or tree nut ingredients.

Storage

Store in a cool, dry place after opening.

Seals/Symbols

GMP Quality Assured

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

Celadrin & MSM by NOW label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

Celadrin & MSM label

Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.

View the full label (PDF)
What’s inside

The Ingredients in Celadrin & MSM by NOW

These are the 7 active ingredients this product is made of. Select any to open its full monograph.

Serving size3 Capsule(s) Dosage formCapsule Servings per container40 Amounts shown are per serving.

Most supplement products combine several ingredients, and a medication can interact with the product through any one of them. Each ingredient below shows whether it has known drug interactions.

MSM

300 mg per serving

Celadrin

1.5 Gram(s) per serving
  • › Vitamin A Palmitate
  • › Cetyl Myristoleate
  • › Cetyl Myristate
  • › Cetyl Laurate
  • › Cetyl Palmitoleate
  • › Cetyl Oleate

Other (inactive) ingredients: Gelatin, Sodium Copper Chlorophyllin, Magnesium Stearate, Silica. These complete the product’s ingredient list but are not active constituents.

Interaction report

Celadrin & MSM by NOW Drug Interactions

Want to check YOUR meds against Celadrin & MSM?

Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.

 Go to the checker
387Drugs
9 Major 378 Moderate

Ingredients driving the most interactions

Vitamin A Palmitate 387

Individual Drug Interactions

The ingredients in Celadrin & MSM interact with 387 drugs. Click any drug to see the details.

1 of the 7 ingredients in Celadrin & MSM interact with drugs. Each result below shows which ingredient is responsible. Vitamin A Palmitate

Each ingredient & the kinds of drugs it affects

For each ingredient in Celadrin & MSM with known interactions, here are the types of medications it can affect. Open any type for the detail — or search your exact drug in the checker above.

Vitamin A Palmitate4 drug types · 387 drugs

Retinoids

Concomitant use of retinoids with vitamin A supplements might produce supratherapeutic vitamin A levels.
Retinoids, which are vitamin A derivatives, could have additive toxic effects when taken with vitamin A supplements.

Likelihood Probable Evidence D
Hepatotoxic Drugs

Theoretically, taking high doses of vitamin A in combination with other potentially hepatotoxic drugs might increase the risk of liver disease.
The tolerable upper intake level (UL) is the highest level of intake that is likely to pose no risk of adverse effects. Doses of vitamin A above the UL can cause hepatotoxicity, ranging from elevated liver enzymes to liver failure.

Likelihood Possible Evidence C
Tetracycline Antibiotics

Theoretically, taking tetracycline antibiotics with high doses of vitamin A can increase the risk of pseudotumor cerebri.
Benign intracranial hypertension (pseudotumor cerebri) can occur with tetracyclines and with acute or chronic vitamin A toxicity. Case reports suggest that taking tetracyclines and vitamin A concurrently can increase the risk of this condition. Avoid high doses of vitamin A in people taking tetracyclines chronically.

Likelihood Possible Evidence D
Warfarin (Coumadin)

Theoretically, high doses of vitamin A could increase the risk of bleeding with warfarin.
Vitamin A toxicity is associated with hemorrhage and hypoprothrombinemia, possibly due to vitamin K antagonism. Advise patients taking warfarin to avoid doses of vitamin A above the tolerable upper intake level of 10,000 IU/day for adults.

Likelihood Possible Evidence D
Vitamin A Palmitate full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Celadrin & MSM, from the product label.

NOW

See all NOW products
Name
NOW Foods
Street Address
395 S. Glen Ellyn Rd.
City
Bloomingdale
State
IL
ZipCode
60108
Web Address
nowfoods.com
Pharmacist Counseling Corner

Celadrin & MSM by NOW: Common Questions

Does Celadrin & MSM by NOW interact with any medications?
Yes. Based on its ingredients, Celadrin & MSM has a known interaction with 387 medications, including 9 rated major. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Celadrin & MSM contains 7 active ingredients, and an interaction can come from any of them. We check every ingredient, combine the results into one list per medication, and show which ingredient and mechanism is responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Does this product have any fillers?
It has four inactive ingredients: gelatin, sodium copper chlorophyllin, magnesium stearate, and silica. These are excipients that make the capsule work, not active ingredients.
Can I take this if I'm pregnant?
The data shows vitamin A at recommended amounts is likely safe in pregnancy, but high doses — especially as retinol — can cause birth defects. Since this product contains vitamin A palmitate, talk with your doctor or pharmacist about whether the dose in this capsule is right for you during pregnancy.
What is vitamin A palmitate used for?
It's a form of vitamin A that's effective for vitamin A deficiency. The data also shows it may help with oral leukoplakia, aging skin, measles, ulcerative colitis, and a lung condition called bronchopulmonary dysplasia, though the evidence for those is not as strong.
What happens if I take too much of this product?
Vitamin A builds up in your body, so high doses can cause toxicity over time. Symptoms include dry, cracking, itchy skin, skin peeling, brittle nails, hair loss, and gum problems. Rare serious effects include liver damage and a condition called benign intracranial hypertension. Always stick to the label dose.
Why can't you check the other ingredients for drug interactions?
We hold no interaction data on file for MSM or the cetyl compounds in this product, so we can't tell you whether they interact with your medications. The only ingredient we could fully check is vitamin A palmitate.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Not sure if Celadrin & MSM is safe with your meds?

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Ask a pharmacist

Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

Celadrin & MSM label
Go deeper

The Full Monographs Behind Celadrin & MSM’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Herb & supplement monograph

Vitamin A

Interacts with 387 drugs

Vitamin A is an essential nutrient important for vision, skin, immune function, and growth. Most people get enough from a balanced diet, and supplements are mainly useful for correcting a tr...

Read the full Vitamin A monograph →
Sources

Sources & How We Checked

Celadrin & MSM's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

The 31 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Vitamin A 31 references
  1. McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
  2. Griffiths JK. The vitamin A paradox. J Pediatr 2000;137:604-7.. PubMed
  3. Hardman JG, Limbird LL, Molinoff PB, eds. Goodman and Gillman's The Pharmacological Basis of Therapeutics, 9th ed. New York, NY: McGraw-Hill, 1996.
  4. Hansten PD, Horn JR. Drug Interactions Analysis and Management. Vancouver, WA: Applied Therapeutics Inc., 1997 and updates.
  5. FDA Talk Paper. Vitamin A and birth defects (T95-56). Food and Drug Administration, U.S. Department of Health and Human Services, Rockville, MD. October 6, 1995.
  6. Russell RM. The vitamin A spectrum: from deficiency to toxicity. Am J Clin Nutr 2000;71:878-84. PubMed
  7. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. Washington, DC: National Academy Press, 2002.
  8. Feskanich D, Singh V, Willett WC, Colditz GA. Vitamin A intake and hip fractures among postmenopausal women. JAMA 2002;287:47-54. PubMed
  9. Melhus H, Michaelsson K, Kindmark A, et al. Excessive dietary intake of vitamin A is associated with reduced bone mineral density and increased risk for hip fracture. Ann Intern Med 1998;129:770-8. PubMed
  10. Michaelsson K, Lithell H, Vessby B, Melhus H. Serum retinol levels and the risk of fracture. N Engl J Med 2003;348:287-94.. PubMed
  11. Botterweck AA, van den Brandt PA, Goldbohm RA. Vitamins, carotenoids, dietary fiber, and the risk of gastric carcinoma: results from a prospective study after 6.3 years of follow-up. Cancer 2000;88:737-48.. DOI
  12. Meyskens FL Jr, Graham V, Chvapil M, et al. A phase I trial of beta-all-trans-retinoic acid delivered via a collagen sponge and a cervical cap for mild or moderate intraepithelial cervical neoplasia. J Natl Cancer Inst 1983;71:921-5..
  13. Hathcock JN, Hattan DG, Jenkins MY, et al. Evaluation of vitamin A toxicity. Am J Clin Nutr 1990;52:183-202.. PubMed
  14. Walters BN, Gubbay SS. Tetracycline and benign intracranial hypertension: report of five cases. Br Med J 1981;282:19-20.. PubMed
  15. Pearson MG, Littlewood SM, Bowden AN. Tetracycline and benign intracranial hypertension (letter). Br Med J 1981;282:568-9.. PubMed
  16. Azais-Braesco V, Pascal G. Vitamin A in pregnancy: requirements and safety limits. Am J Clin Nutr 2000;71:1325S-33S. PubMed
  17. Smedts HP, de Vries JH, Rakhshandehroo M, et al. High maternal vitamin E intake by diet or supplements is associated with congenital heart defects in the offspring. BJOG 2009;116:416-23. PubMed
  18. Grotto, I., Mimouni, M., Gdalevich, M., and Mimouni, D. Vitamin A supplementation and childhood morbidity from diarrhea and respiratory infections: a meta-analysis. J Pediatr 2003;142(3):297-304. PubMed
  19. Mahalanabis, D., Lahiri, M., Paul, D., Gupta, S., Gupta, A., Wahed, M. A., and Khaled, M. A. Randomized, double-blind, placebo-controlled clinical trial of the efficacy of treatment with zinc or vitamin A in infants and young children with severe acute l
  20. Long, K. Z., Montoya, Y., Hertzmark, E., Santos, J. I., and Rosado, J. L. A double-blind, randomized, clinical trial of the effect of vitamin A and zinc supplementation on diarrheal disease and respiratory tract infections in children in Mexico City, Mex
  21. Fritz, H., Kennedy, D., Fergusson, D., Fernandes, R., Doucette, S., Cooley, K., Seely, A., Sagar, S., Wong, R., and Seely, D. Vitamin A and retinoid derivatives for lung cancer: a systematic review and meta analysis. PLoS.One. 2011;6(6):e21107. PubMed
  22. Mayo-Wilson, E., Imdad, A., Herzer, K., Yakoob, M. Y., and Bhutta, Z. A. Vitamin A supplements for preventing mortality, illness, and blindness in children aged under 5: systematic review and meta-analysis. BMJ 2011;343:d5094. PubMed
  23. Mazumder S, Taneja S, Bhatia K, Yoshida S, Kaur J, Dube B, Toteja GS, Bahl R, Fontaine O, Martines J, Bhandari N; Neovita India Study Group. Efficacy of early neonatal supplementation with vitamin A to reduce mortality in infancy in Haryana, India (Neovit
  24. Baineni R, Gulati R, Delhi CK. Vitamin A toxicity presenting as bone pain. Arch Dis Child. 2017;102(6):556-8. PubMed
  25. Darlow BA, Graham PJ, Rojas-Reyes MX. Vitamin A supplementation to prevent mortality and short- and long-term morbidity in very low birth weight infants. Cochrane Database Syst Rev. 2016;(8):CD000501. PubMed
  26. Haider BA, Sharma R, Bhutta ZA. Neonatal vitamin A supplementation for the prevention of mortality and morbidity in term neonates in low and middle income countries. Cochrane Database Syst Rev. 2017;2:CD006980. PubMed
  27. Mohammad YM, Raslan IR, Al-Hussain FA. Idiopathic Intracranial Hypertension Induced by Topical Application of Vitamin A. J Neuroophthalmol. 2016;36(4):412-3. PubMed
  28. Masnadi Shirazi K, Nikniaz Z, Masnadi Shirazi A, Rohani M. Vitamin A supplementation decreases disease activity index in patients with ulcerative colitis: A randomized controlled clinical trial. Complement Ther Med. 2018 Dec;41:215-219. PubMed
  29. Ding Y, Hu P, Yang Y, et al. Impact of maternal daily oral low-dose vitamin A supplementation on the mother-infant pair: a randomised placebo-controlled trial in China. Nutrients 2021;13(7):2370. PubMed
  30. Knapik JJ, Hoedebecke SS. Vitamin A and bone fractures: systematic review and meta-analysis. J Spec Oper Med 2021;21(2):100-7. PubMed
  31. Imdad A, Mayo-Wilson E, Haykal MR, et al. Vitamin A supplementation for preventing morbidity and mortality in children from six months to five years of age. Cochrane Database Syst Rev 2022;3(3):CD008524. PubMed

See these in context on the Vitamin A monograph →

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

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