Interactions on record — worth a quick check against your medications. Based on 1 of 2 ingredients. Check your meds →
Dietary supplement

D, L-Phenylalanine 750 mg Ingredients & Drug Interactions

by Metabolic Maintenance

Capsule Category: Other Combinations
Most serious interaction: Moderate
The interaction bottom line Most serious interaction: Moderate

D, L-Phenylalanine 750 mg is a dietary supplement by Metabolic Maintenance with 2 active ingredients. Its ingredients are commonly taken for morning sickness in pregnancy, premenstrual syndrome (pms), preventing or treating b6 deficiency.Based on those ingredients, 210 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Vitamin B6. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

HelloPharmacist Scorecard of D, L-Phenylalanine 750 mg by Metabolic Maintenance

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

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 2 of its 2 active ingredients.
  • No proprietary blends here — you can verify the dose of every single component.

This product contains 2 active ingredients: vitamin B6 and DL-Phenylalanine (750 mg per capsule). The capsule itself is made from cellulose, with L-leucine as an additional ingredient.

Vitamin B6 is a B-complex vitamin your body uses for nerve function, immune health, and helping break down proteins and carbohydrates. DL-Phenylalanine is an amino acid — though we have limited interaction data on file for it.

Does it work?

Strong evidence
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

This product doesn't appear to be marketed for a specific use, so we graded Vitamin B6's overall clinical evidence instead.

Strong

Strong clinical evidence supports Vitamin B6 for:

Why this rating?
  • We looked at the product name, claims, and label statements and couldn't find a stated purpose to grade.
  • Since the label doesn't commit to one use, we graded the ingredient's overall clinical evidence instead.
  • On file: Sideroblastic anemia — rated "Effective" (Natural Medicines).
  • On file: Vitamin B6 deficiency — rated "Effective" (Natural Medicines).
  • On file: Pyridoxine-dependent epilepsy — rated "Effective" (Natural Medicines).
  • On file: Hyperhomocysteinemia — rated "Likely Effective" (Natural Medicines).
  • On file: Antipsychotic-induced hyperprolactinemia — rated "Possibly Effective" (Natural Medicines).

Vitamin B6 is effective for sideroblastic anemia (a blood condition) and B6 deficiency itself, and it's proven to work for a rare seizure disorder called pyridoxine-dependent epilepsy. It's likely effective for lowering high homocysteine levels and possibly effective for pregnancy-related nausea and vomiting.

We don't have effectiveness data on file for DL-Phenylalanine.

The evidence, ingredient by ingredient Vitamin B6

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 B6 is well tolerated at doses under 100 mg daily. Common side effects at higher doses include headache, nausea, heartburn, and loss of appetite.

The main safety concern is sensory nerve damage (neuropathy) — it's rare but can happen with daily doses above 1,000 mg or total lifetime doses of 1 gram or more, though it can occur at lower doses too. Avoid high doses long-term unless a doctor directs you otherwise.

For pregnancy, vitamin B6 is likely safe, though there's also a possibly unsafe rating depending on dose and context — talk with your doctor about your specific situation. It's likely safe during breastfeeding.

We have no pregnancy or breastfeeding data on file for DL-Phenylalanine.

Side effects, ingredient by ingredient Vitamin B6

Meds to double-check

Moderate interaction found
Known Interaction Concern · database check
Moderate identified

The most serious documented interaction for these ingredients is Moderate. Check your medications for a personalized result.

Why this rating?
  • 1 of the 1 matched ingredient can interact with medications — Vitamin B6.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: Parkinson's medications.
  • For scale: 210 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.

Check with your doctor or pharmacist before taking this if you use seizure medications (phenobarbital, phenytoin), blood pressure drugs, the heart medication amiodarone, or levodopa for Parkinson's disease. We couldn't check the DL-Phenylalanine ingredient for interactions, so mention the full product name when you ask.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with strong clinical evidence behind its ingredients' uses. Moderate medication interactions have been identified, and safety information is well characterized.

This product is worth considering if you're low in vitamin B6 or dealing with certain blood or neurological conditions, but you'll want to check your medications first — especially seizure drugs, blood pressure pills, and amiodarone. Keep doses moderate and long-term use short unless your doctor says otherwise.

Talk with your own doctor or pharmacist before starting, particularly if you're pregnant, taking prescriptions, or planning to use this regularly.

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

Assessment coverage: 1 of 2 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Sep 22, 2022.

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 D, L-Phenylalanine 750 mg, straight from the product label.

Brand Metabolic Maintenance
Barcode (UPC) 838287001140
Net contents 60 Capsule(s)
Market status On market
Date entered into DSLD Sep 22, 2022
DSLD ID 274026
Product type Other Combinations
Supplement form Capsule
Dietary claims / uses All Other
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 D, L-Phenylalanine 750 mg by Metabolic Maintenance, 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:
1 Capsule(s)
Maximum serving Sizes:
1 Capsule(s)
Servings per container
60
UPC/BARCODE
838287001140
IngredientAmount% DV
Vitamin B615 mg882%
DL-Phenylalanine750 mg--

Other ingredients: Cellulose, L-Leucine

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.
Precautions

Caution: Phenylketonurics contains phenylalanine. Do not take with MAO inhibitors or tricyclic antidepressants.

Hypertensives, pregnant or lactating women, consult your healthcare professional before taking this product.

Keep tightly closed in a cool, dry place, out of the reach of children.

Storage

Keep tightly closed in a cool, dry place, out of the reach of children.

Formulation

Egg free Gluten free Free of nuts Dairy free

Manufactured in a GMP Compliant Facility

FDA Statement of Identity

Dietary Supplement

Suggested/Recommended/Usage/Directions

Directions: One (1) capsule daily, or as directed by a healthcare professional. Best taken between meals.

See for yourself

D, L-Phenylalanine 750 mg by Metabolic Maintenance label

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

What’s inside

The Ingredients in D, L-Phenylalanine 750 mg by Metabolic Maintenance

These are the 2 active ingredients this product is made of. Select any to open its full monograph.

Serving size1 Capsule(s) Dosage formCapsule Servings per container60 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.

Vitamin B6

Interacts with
210 drugs
15 mg per serving Form: Pyridoxine Hydrochloride

Vitamin B6 (pyridoxine) is an essential water-soluble vitamin that your body needs for metabolism, brain function, and making red blood cells. It is b...

Vitamin B6 monograph & interactions

DL-Phenylalanine

750 mg per serving

Other (inactive) ingredients: Cellulose, L-Leucine. These complete the product’s ingredient list but are not active constituents.

Interaction report

D, L-Phenylalanine 750 mg by Metabolic Maintenance Drug Interactions

Want to check YOUR meds against D, L-Phenylalanine 750 mg?

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
210Drugs
205 Moderate 5 Minor

Ingredients driving the most interactions

Each ingredient & the kinds of drugs it affects

For each ingredient in D, L-Phenylalanine 750 mg 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 B65 drug types · 210 drugs

Amiodarone (Cordarone)

Theoretically, vitamin B6 might increase the photosensitivity caused by amiodarone.
Despite initial case reports suggesting that pyridoxine may have a protective effect against amiodarone-induced photosensitivity, preliminary clinical research suggests that pyridoxine may actually exacerbate this adverse effect.

Likelihood Possible Evidence B
Antihypertensive Drugs

Theoretically, vitamin B6 may have additive effects when used with antihypertensive drugs.
Research in hypertensive rats shows that vitamin B6 can decrease systolic blood pressure. Similarly, clinical research in patients with hypertension shows that taking high doses of vitamin B6 may reduce systolic and diastolic blood pressure, possibly by reducing plasma levels of epinephrine and norepinephrine.

Likelihood Possible Evidence B
Phenobarbital (Luminal)

High doses of vitamin B6 may reduce the levels and clinical effects of phenobarbital.
Preliminary clinical evidence suggests that vitamin B6 200 mg daily can reduce plasma levels of phenobarbital, possibly by increasing metabolism. It is not known whether lower doses have any effect. Advise people taking phenobarbital to avoid high doses of vitamin B6.

Likelihood Possible Evidence D
Phenytoin (Dilantin)

High doses of vitamin B6 may reduce the levels and clinical effects of phenytoin.
Preliminary clinical evidence suggests that vitamin B6 200 mg daily can reduce plasma levels of phenytoin, possibly by increasing metabolism. It is not known whether lower doses have any effect. Advise people taking phenytoin to avoid high doses of vitamin B6.

Likelihood Possible Evidence D
Levodopa

Vitamin B6 may increase the metabolism of levodopa when taken alone, but not when taken in conjunction with carbidopa.
Vitamin B6 (pyridoxine) enhances the metabolism of levodopa, reducing its clinical effects. However, this interaction does not occur when carbidopa is used concurrently with levodopa (Sinemet). Therefore, it is not likely to be a problem in most people.

Likelihood Unlikely Evidence D
The maker

Brand information

Manufacturer and brand details for D, L-Phenylalanine 750 mg, from the product label.

Metabolic Maintenance

See all Metabolic Maintenance products
Name
Metabolic Maintenance
Street Address
601 N Larch Street
City
Sisters
State
Oregon
ZipCode
97759
Phone Number
800-772-7873
Web Address
MetabolicMaintenance.com
Pharmacist Counseling Corner

D, L-Phenylalanine 750 mg by Metabolic Maintenance: Common Questions

Does D, L-Phenylalanine 750 mg by Metabolic Maintenance interact with any medications?
Yes. Based on its ingredients, D, L-Phenylalanine 750 mg has a known interaction with 210 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
D, L-Phenylalanine 750 mg contains 2 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.
Is this safe to take while pregnant?
Vitamin B6 is rated likely safe in pregnancy at standard doses, but there's also a possibly unsafe rating depending on the dose and circumstance. We have no data on DL-Phenylalanine. Talk with your doctor about whether this product is right for your situation.
Can I take this long-term?
Not without caution. High doses of vitamin B6 over time can damage nerves — especially daily doses over 1,000 mg or lifetime totals of 1 gram or more. Stick to short-term use unless your doctor advises a longer course.
What is DL-Phenylalanine used for?
DL-Phenylalanine is an amino acid, but we don't have effectiveness data on file for it. Talk with your pharmacist about what role it plays in this particular formulation.
What side effects should I watch for?
At moderate doses, vitamin B6 may cause headache, nausea, or loss of appetite. At high doses or with long-term use, sensory nerve damage can occur, causing tingling or numbness. Stop and contact your doctor if you notice any nerve-related symptoms.
Can I take this with my blood pressure medication?
Not without checking first. Vitamin B6 can add to the blood pressure-lowering effect of antihypertensive drugs, which could cause your pressure to drop too far. Run your specific medication through the interaction checker below, or ask your pharmacist.
Will this interact with my seizure medication?
Possibly. High doses of vitamin B6 may reduce how well phenobarbital and phenytoin work. If you take either of those, check with your doctor before starting this product.

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

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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.

D, L-Phenylalanine 750 mg label
Go deeper

The Full Monographs Behind D, L-Phenylalanine 750 mg’s Ingredients

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

Sources

Sources & How We Checked

D, L-Phenylalanine 750 mg'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 32 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 B6 32 references
  1. Hansten PD, Horn JR. Drug Interactions Analysis and Management. Vancouver, WA: Applied Therapeutics Inc., 1997 and updates.
  2. Yates AA, Schlicker SA, Suitor CW. Dietary reference intakes: The new basis for recommendations for calcium and related nutrients, B vitamins, and choline. J Am Diet Assoc 1998;98:699-706. PubMed
  3. Geerling BJ, Dagnelie PC, Badart-Smook A, et al. Diet as a risk factor for the development of ulcerative colitis. Am J Gastroenterol 2000;95:1008-13. PubMed
  4. South M. Neonatal seizures after pyridoxine use -- reply. Lancet 1999;354:2083. PubMed
  5. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline (2000). Washington, DC: National Academy Press, 2000. Available at: http://b
  6. Baxter P, Aicardi J. Neonatal seizures after pyridoxine use. Lancet 1999;354:2082-3. PubMed
  7. Bendich A, Cohen M. Vitamin B6 safety issues. Ann N Y Acad Sci 1990;585:321-30.
  8. Schaumburg H, Kaplan J, Windebank A. Sensory neuropathy from pyridoxine abuse. A new megavitamin syndrome. N Engl J Med 1983;309:445-8. PubMed
  9. Gordon N. Pyridoxine dependency: an update. Dev Med Child Neurol 1997;39:63-5. PubMed
  10. Lewis PJ. Pain in the hand and wrist. Pyridoxine supplements may help patients with carpal tunnel syndrome. BMJ 1995;310:1534. PubMed
  11. Kaufman G. Pyridoxine against amiodarone-induced photosensitivity (letter). Lancet 1984;1:51-2. PubMed
  12. Mulrow JP, Mulrow CD, McKenna WJ. Pyridoxine and amiodarone-induced photosensitivity. Ann Intern Med 1985;103:68-9. PubMed
  13. Kawada A, Kashima A, Shiraishi H, et al. Pyridoxine-induced photosensitivity and hypophosphatasia. Dermatology 2000;201:356-60.. PubMed
  14. Vasile A, Goldberg R, Kornberg B. Pyridoxine toxicity: report of a case. J Am Osteopath Assoc 1984;83:790-1. DOI
  15. Hansson O, Sillanpaa M. Pyridoxine and serum concentration of phenytoin and phenobarbitone. Lancet 1976;1:256. DOI
  16. Jansen T, Romiti R, Kreuter A, Altmeyer P. Rosacea fulminans triggered by high-dose vitamins B6 and B12. J Eur Acad Dermatol Venereol 2001;15:484-5..
  17. Chittumma P, Kaewkiattikun K, Wiriyasiriwach B. Comparison of the effectiveness of ginger and vitamin B6 for treatment of nausea and vomiting in early pregnancy: a randomized double-blind controlled trial. J Med Assoc Thai 2007;90:15-20.
  18. Hatzitolios, A., Iliadis, F., Katsiki, N., and Baltatzi, M. Is the anti-hypertensive effect of dietary supplements via aldehydes reduction evidence based? A systematic review. Clin Exp.Hypertens. 2008;30(7):628-639. PubMed
  19. Vasdev, S., Ford, C. A., Parai, S., Longerich, L., and Gadag, V. Dietary vitamin B6 supplementation attenuates hypertension in spontaneously hypertensive rats. Mol.Cell Biochem. 1999;200(1-2):155-162.
  20. de, Vogel S., Dindore, V., van, Engeland M., Goldbohm, R. A., van den Brandt, P. A., and Weijenberg, M. P. Dietary folate, methionine, riboflavin, and vitamin B-6 and risk of sporadic colorectal cancer. J Nutr 2008;138(12):2372-2378. PubMed
  21. Hagen, I., Nesheim, B. I., and Tuntland, T. No effect of vitamin B-6 against premenstrual tension. A controlled clinical study. Acta Obstet.Gynecol.Scand. 1985;64(8):667-670. PubMed
  22. Aybak, M., Sermet, A., Ayyildiz, M. O., and Karakilcik, A. Z. Effect of oral pyridoxine hydrochloride supplementation on arterial blood pressure in patients with essential hypertension. Arzneimittelforschung. 1995;45(12):1271-1273.
  23. Lal, K. J., Dakshinamurti, K., and Thliveris, J. The effect of vitamin B6 on the systolic blood pressure of rats in various animal models of hypertension. J Hypertens. 1996;14(3):355-363. PubMed
  24. Lauritzen CH, Reuter HD, Repges R, Bohnert K, and Schmidt U. Treatment of premenstrual tension syndrome with Vitex agnus castus. Controlled, double-blind study versus pyridoxine. Phytomed 1997;4(3):183-189. PubMed
  25. Fonseca VA, Lavery LA, Thethi TK, et al. Metanx in type 2 diabetes with peripheral neuropathy: A randomized trial. Am J Med 2013;126(2):141-9. PubMed
  26. Hankey GJ, Eikelboom JW, Yi Q, et al. Treatment with B vitamins and incidence of cancer in patients with previous stroke or transient ischemic attack: Results of a randomized placebo-controlled trial. Stroke 2012;43(6):1572-7. PubMed
  27. Hoyer-Kuhn H, Kohbrok S, Volland R, Franklin J, Hero B, Beck BB, Hoppe B. Vitamin B6 in primary hyperoxaluria I: first prospective trial after 40 years of practice. Clin J Am Soc Nephrol. 2014 Mar;9(3):468-77. PubMed
  28. Mahmoud A, Tabassum S, Al Enazi S, et al. Amelioration of levetiracetam-induced behavioral side effects by pyridoxine. A randomized double blind controlled study. Pediatr Neurol 2021;119:15-21. PubMed
  29. Gupta M, Gallante B, Bamberger JN, et al. Prospective randomized evaluation of idiopathic hyperoxaluria treatments. J Endourol 2021;35(12):1844-1851. PubMed
  30. Li H, Chen M, Liang S, et al. Excessive vitamin B6 during treatment is related to poor prognosis of patients with nasopharyngeal carcinoma: A U-shaped distribution suggests low dose supplement. Clin Nutr 2021;40(4):2293-2300. PubMed
  31. Tanigawa J, Nabatame S, Tominaga K, et al. High-dose pyridoxine treatment for inherited glycosylphosphatidylinositol deficiency. Brain Dev 2021;43(6):680-687. PubMed
  32. Committee on Practice Bulletins-Obstetrics. ACOG Practice Bulletin No. 189: Nausea And Vomiting Of Pregnancy. Obstet Gynecol. 2018;131(1):e15-e30. PubMed

See these in context on the Vitamin B6 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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