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Dietary supplement

CysteinePep Ingredients & Drug Interactions

by NutriCology

CysteinePep label
See full label image
Capsule Category: Amino Acid/protein
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 CysteinePep 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

CysteinePep is a dietary supplement by NutriCology with 1 active ingredient. Its ingredients are commonly taken for muscle building and recovery, increasing daily protein intake, weight management.Based on those ingredients, 53 medications have a known interaction with it, the most serious rated major. The ingredients most likely to interact are Whey Protein Hydrolysate. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against CysteinePep by NutriCology

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

Pharmacist-reviewed data Checks every ingredient Answer in seconds
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HelloPharmacist Scorecard of CysteinePep by NutriCology

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

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 1 of its 1 active ingredient.
  • No proprietary blends here — you can verify the dose of every single component.

CysteinePep has one active ingredient: whey protein hydrolysate, a processed form of whey that's been broken down into smaller pieces so your body can absorb it more easily. The capsule itself is made of gelatin, an inactive ingredient.

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 Whey Protein's own graded uses on its monograph.

Why this rating?
  • The label markets this product for: glutathione production and antioxidant support.
  • We looked for evidence on: Asthma, Atopic dermatitis (eczema), Atopic disease, Chronic obstructive pulmonary disease (COPD), Cystic fibrosis, Exercise-induced asthma — and 4 related terms.
  • The closest evidence on file: Whey Protein is rated "Possibly Ineffective" for Chronic obstructive pulmonary disease (COPD) (Natural Medicines).
  • Also on file: Whey Protein is rated "Insufficient Reliable Evidence To Rate" for HIV/AIDS-related wasting, Asthma, Atopic disease, Cystic fibrosis, and more.

Whey protein is possibly effective for athletic performance. For bone health (osteoporosis), the evidence suggests it's possibly ineffective.

The data we hold doesn't establish whether it helps with age-related cognitive decline, COPD, or HIV/AIDS-related wasting — the evidence on those isn't reliable enough to rate.

The evidence, ingredient by ingredient Whey Protein

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.

Whey protein hydrolysate is generally well tolerated by most healthy adults at normal doses. Common side effects are dose-related and include bloating, cramps, diarrhea, nausea, headache, fatigue, reduced appetite, reflux, and thirst.

Acne has been reported, especially in teenagers and young adults; stopping whey protein usually clears it. Because concentrated supplement products haven't been studied as thoroughly as whole whey food, check with your doctor before starting, especially at high doses.

Side effects, ingredient by ingredient Whey Protein

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 — Whey Protein.
  • The most serious interaction on file is rated Major.
  • Some involve high-stakes drug classes: Parkinson's medications.
  • For scale: 53 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 taking CysteinePep, double-check if you're on levodopa (Major severity) — the whey protein can make it less effective and worsen symptoms. Also check for any quinolone or tetracycline antibiotics, and bisphosphonates (all Moderate) — timing matters to avoid reducing their absorption.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with no established evidence rating for its marketed use. Major medication interactions have been identified, and safety information is well characterized.

This product may work for athletic performance, but if you take levodopa for Parkinson disease or any quinolone, tetracycline, or bisphosphonate medication, you need to check your exact drugs with the tool below and likely space out the timing. Talk to your pharmacist before you start, particularly if you're on any regular prescriptions.

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

Assessment coverage: 1 of 1 active ingredient matched to our full ingredient reviews (monographs). Based on the product label dated Dec 23, 2011.

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 CysteinePep, straight from the product label.

Brand NutriCology
Barcode (UPC) 713947556409
Net contents 150 Capsule(s)
Market status On market
Date entered into DSLD Dec 23, 2011
DSLD ID 2996
Product type Amino Acid/protein
Supplement form Capsule
Dietary claims / uses All Other
Intended target group(s) Adult (18 - 50 Years)
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 CysteinePep by NutriCology, 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:
5 Capsule(s)
Maximum serving Sizes:
5 Capsule(s)
Servings per container
30
UPC/BARCODE
713947556409
IngredientAmount% DV
Whey Protein Hydrolysate3.5 g--

Other ingredients: Gelatin

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.
Formula

CysteinePep is hydrolysed whey protein containing cysteine in peptide-bonded form, which supports glutathione production via the liver and acts as a precursor to glutathione, one of the most powerful antioxidant nutrients.

Suggested/Recommended/Usage/Directions

Suggested Use As a dietary supplement, 5 capsules daily, or as directed by a healthcare practitioner.

Storage

Keep in a cool, dry place, tightly capped.

General Statements

Innovative Nutrition

FDA Statement of Identity

Dietary Supplement

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

See for yourself

CysteinePep by NutriCology label

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

CysteinePep 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 CysteinePep by NutriCology

This is the 1 active ingredient this product is made of. Select it to open its full monograph.

Serving size5 Capsule(s) Dosage formCapsule Servings per container30 Amounts shown are per serving.

Whey Protein Hydrolysate

Interacts with
53 drugs
3.5 g per serving Form: Milk

Whey protein is a high-quality, complete protein made from cow's milk that can help people meet protein needs and support muscle growth when combined...

Whey Protein Hydrolysate monograph & interactions

Other (inactive) ingredients: Gelatin. These complete the product’s ingredient list but are not active constituents.

Interaction report

CysteinePep by NutriCology Drug Interactions

Want to check YOUR meds against CysteinePep?

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
53Drugs
5 Major 48 Moderate

Ingredients driving the most interactions

Whey Protein Hydrolysate 53

Individual Drug Interactions

The ingredients in CysteinePep interact with 53 drugs. Click any drug to see the details.

1 of the 1 ingredient in CysteinePep interact with drugs. Each result below shows which ingredient is responsible. Whey Protein Hydrolysate

Each ingredient & the kinds of drugs it affects

For each ingredient in CysteinePep 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.

Whey Protein Hydrolysate4 drug types · 53 drugs

Levodopa

Theoretically, whey protein might decrease levodopa absorption.
Small clinical studies show that concomitant ingestion of protein or high doses of leucine or isoleucine (100 mg/kg) and levodopa can exacerbate tremor, rigidity, and the "on-off" syndrome in patients with Parkinson disease.

Likelihood Probable Evidence D
Bisphosphonates

Theoretically, whey protein might reduce the absorption of bisphosphonates.
Whey protein contains minerals such as calcium that bind bisphosphonates in the gut. Advise patients to take bisphosphonates at least 30 minutes before whey protein, but preferably at a different time of day.

Likelihood Probable Evidence D
Quinolone Antibiotics

Theoretically, whey protein might decrease quinolone absorption.
Whey protein contains minerals, such as calcium, that can bind to quinolones in the gut. To avoid this interaction, advise patients to take oral quinolones at least 2 hours before or 4-6 hours after whey protein.

Likelihood Probable Evidence D
Tetracycline Antibiotics

Theoretically, whey protein might decrease tetracycline absorption.
Whey protein contains minerals, such as calcium, that bind to tetracyclines in the gut. To avoid this interaction, advise patients to take oral tetracyclines at least 2 hours before or 4-6 hours after whey protein.

Likelihood Probable Evidence D
Whey Protein Hydrolysate full monograph & interactions
The maker

Brand information

Manufacturer and brand details for CysteinePep, from the product label.

NutriCology

See all NutriCology products
Name
NutriCology, Inc.
City
Alameda
State
CA
ZipCode
94502
Web Address
www.nutricology.com
Pharmacist Counseling Corner

CysteinePep by NutriCology: Common Questions

Does CysteinePep by NutriCology interact with any medications?
Yes. Based on its ingredients, CysteinePep has a known interaction with 53 medications, including 5 rated major. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
CysteinePep contains a single active ingredient, and that one ingredient can interact with many different medications on its own. We check it against each medication and show the mechanism 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.
Can I take this while I'm pregnant or nursing?
We don't have safety data on file for whey protein during pregnancy or lactation. Talk with your doctor or pharmacist — they can give you personalized advice based on your situation.
What's the difference between whey protein in food and this supplement?
Whey as a regular food protein is fine, but concentrated supplement products like this haven't been studied as much. That's why we recommend checking with your doctor before starting, especially at higher doses.
Does whey protein actually build muscle and improve athletic performance?
The evidence says it's possibly effective for athletic performance. Whether it works best depends on your training and overall diet — your goals and routine matter.
What should I do if I get acne after starting CysteinePep?
Acne has been reported with whey protein, particularly in younger adults. If it develops, stopping the supplement usually clears it. If you're having trouble with acne treatments while taking whey protein, stopping may help — talk to your doctor.
Will this help my bones if I have osteoporosis?
The evidence we have suggests whey protein is possibly ineffective for osteoporosis, so it may not be the right choice for that purpose.
What's in the capsule besides the whey protein?
The capsule is made of gelatin, which is an inactive ingredient. There are no other fillers or additives.

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

Not sure if CysteinePep is safe with your meds?

Our pharmacists answer your medication & supplement questions — free.

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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.

CysteinePep label
Go deeper

The Full Monographs Behind CysteinePep’s Ingredients

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

Herb & supplement monograph

Whey Protein

Interacts with 53 drugs

Whey protein is a high-quality, complete protein made from cow's milk that can help people meet protein needs and support muscle growth when combined with exercise. It is generally safe for...

Read the full Whey Protein monograph →
Sources

Sources & How We Checked

CysteinePep'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 25 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.

Whey Protein 25 references
  1. Martindale W. Martindale the Extra Pharmacopoeia. Pharmaceutical Press, 1999.
  2. Maton PN, Burton ME. Antacids revisited: a review of their clinical pharmacology and recommended therapeutic use. Drugs 1999;57:855-70.
  3. Bell SJ. Whey protein concentrates with and without immunoglobulins: a review. J Med Food 2000;3:1-13. PubMed
  4. Nutt JG, Woodward WR, Hammerstad JP, et al. The "on-off" phenomenon in Parkinson's disease. Relation to levodopa absorption and transport. N Engl J Med 1984;310:483-8. PubMed
  5. Baruzzi A, Contin M, Riva R, et al. Influence of meal ingestion time on pharmacokinetics of orally administered levodopa in parkinsonian patients. Clin Neuropharmacol 1987;10:527-37. PubMed
  6. Juncos JL, Fabbrini G, Mouradian MM, et al. Dietary influences on the antiparkinsonian response to levodopa. Arch Neurol 1987;44:1003-5. PubMed
  7. Eriksson T, Granerus AK, Linde A, et al. "On-off" phenomenon in Parkinson's disease: relationship between dopa and other large neutral amino acids in plasma. Neurology 1988;38:1245-8. PubMed
  8. Semla TP, Beizer JL, Higbee MD. Geriatric Dosage Handbook. 4th ed. Hudson, OH: Lexicomp, 1998.
  9. Pletz MW, Petzold P, Allen A, et al. Effect of calcium carbonate on bioavailability of orally administered gemifloxacin. Antimicrob Agents Chemother 2003;47:2158-60.. PubMed
  10. Peters ML, Leonard M, Licata AA. Role of alendronate and risedronate in preventing and treating osteoporosis. Cleve Clin J Med 2001;68:945-51. PubMed
  11. Micke, P., Beeh, K. M., and Buhl, R. Effects of long-term supplementation with whey proteins on plasma glutathione levels of HIV-infected patients. Eur.J Nutr 2002;41(1):12-18. PubMed
  12. Chitapanarux, T., Tienboon, P., Pojchamarnwiputh, S., and Leelarungrayub, D. Open-labeled pilot study of cysteine-rich whey protein isolate supplementation for nonalcoholic steatohepatitis patients. J Gastroenterol.Hepatol. 2009;24(6):1045-1050. PubMed
  13. Sataloff, R. T., Bittermann, T., Marks, L., Lurie, D., and Hawkshaw, M. The effects of glutathione enhancement on sensorineural hearing loss. Ear Nose Throat J 2010;89(9):422-433.
  14. Zhu, K., Meng, X., Kerr, D. A., Devine, A., Solah, V., Binns, C. W., and Prince, R. L. The effects of a two-year randomized, controlled trial of whey protein supplementation on bone structure, IGF-1, and urinary calcium excretion in older postmenopausal
  15. Bjorkman, M. P., Pilvi, T. K., Kekkonen, R. A., Korpela, R., and Tilvis, R. S. Similar effects of leucine rich and regular dairy products on muscle mass and functions of older polymyalgia rheumatica patients: a randomized crossover trial. J Nutr Health A
  16. Brun, A. C., Stordal, K., Johannesdottir, G. B., Bentsen, B. S., and Medhus, A. W. The effect of protein composition in liquid meals on gastric emptying rate in children with cerebral palsy. Clin.Nutr 2012;31(1):108-112. PubMed
  17. Gouni-Berthold, I., Schulte, D. M., Krone, W., Lapointe, J. F., Lemieux, P., Predel, H. G., and Berthold, H. K. The whey fermentation product malleable protein matrix decreases TAG concentrations in patients with the metabolic syndrome: a randomised plac
  18. Errichiello, L., Pezzella, M., Santulli, L., Striano, S., Zara, F., Minetti, C., Mainardi, P., and Striano, P. A proof-of-concept trial of the whey protein alfa-lactalbumin in chronic cortical myoclonus. Mov Disord. 2011;26(14):2573-2575. PubMed
  19. Carcillo, J. A., Dean, J. M., Holubkov, R., Berger, J., Meert, K. L., Anand, K. J., Zimmerman, J., Newth, C. J., Harrison, R., Burr, J., Willson, D. F., and Nicholson, C. The randomized comparative pediatric critical illness stress-induced immune suppres
  20. Chungchunlam, S. M., Moughan, P. J., Henare, S. J., and Ganesh, S. Effect of time of consumption of preloads on measures of satiety in healthy normal weight women. Appetite 2012;59(2):281-288. PubMed
  21. Rencuzogullari I, Börekçi A, Karakoyun S, et al. Coronary thrombosis in three coronary arteries due to whey protein. Am J Emerg Med. 2017;35(4):664.e3-664.e4. PubMed
  22. Silverberg NB. Whey protein precipitating moderate to severe acne flares in 5 teenaged athletes. Case Reports Cutis. 2012;90(2):70-2.
  23. Simonart T. Acne and whey protein supplementation among bodybuilders. Dermatology. 2012;225(3):256-8. PubMed
  24. Pontes TC, Costa Fernandes Filho GM, Pereira Trindade AS, Sobral Filho JF. Incidence of acne vulgaris in young adult users of protein-calorie supplements in the city of João Pessoa-PB. An Bras Dermatol. 2013;88(6):907-12.
  25. Adebamowo CA, Spiegelman D, Berkey CS, et al. Milk consumption and acne in teenaged boys. J Am Acad Dermatol. 2008 May;58(5):787-93. PubMed

See these in context on the Whey Protein 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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