Major interaction on record — check this product against your medications before combining. Based on 3 of 4 ingredients. Check your meds →
Dietary supplement

Formula 594 Ingredients & Drug Interactions

by DC

Capsule Category: Botanical
Most serious interaction: Major
The interaction bottom line Most serious interaction: Major

Formula 594 is a dietary supplement by DC with 4 active ingredients. Its ingredients are commonly taken for erectile dysfunction, low libido, fatigue and low energy.Based on those ingredients, 1,116 medications have a known interaction with it, the most serious rated major. The ingredients most likely to interact are Horny Goat Weed, Mucuna pruriens. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

HelloPharmacist Scorecard of Formula 594 by DC

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 4 of its 4 active ingredients.
  • No proprietary blends here — you can verify the dose of every single component.

Formula 594 contains four active ingredients. Horny Goat Weed and Maca are plant extracts traditionally used to address sexual function and general wellness, though the evidence supporting them is not yet well established.

Mucuna pruriens (also called cowhage) is a legume extract that contains levodopa, an active drug-like compound normally prescribed for Parkinson's disease — it's included here because of its role in dopamine support. We could not verify the interaction profile of Polypodium vulgare extract.

The capsules also contain inactive ingredients (gelatin, vegetable cellulose, vegetable magnesium stearate, and silica) that serve as fillers and binders.

Does it work?

Insufficient 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
Insufficient

There isn't enough reliable clinical evidence to rate this product's ingredients for its stated purpose.

Why this rating?
  • The label markets this product for: Sexual function and male vitality support.
  • We looked for evidence on: Erectile dysfunction (ED), Sexual desire, Sexual dysfunction, Antidepressant-induced sexual dysfunction, Age-related testosterone deficiency, Male infertility — and 4 related terms.
  • The closest evidence on file: Maca is rated "Insufficient Reliable Evidence To Rate" for Antidepressant-induced sexual dysfunction (Natural Medicines).
  • Also on file: Maca is rated "Insufficient Reliable Evidence To Rate" for Athletic performance, Chronic fatigue syndrome (CFS), Fatigue, Sexual desire, and more.

The evidence supporting Formula 594's active ingredients is not well established. Horny Goat Weed has been studied for sexual dysfunction, bronchitis, osteoporosis, and coronary heart disease, but we do not have reliable evidence to rate its effectiveness for any of these uses.

Maca has been studied for sexual function issues, low iron (anemia of chronic disease), athletic performance, and osteoporosis — again, the evidence is insufficient to establish whether it works. Mucuna pruriens has been studied for anxiety, Parkinson's disease, high prolactin levels, and other conditions, but reliable evidence is not available.

Because the evidence is not yet established in our data, talk with your pharmacist or doctor about whether this product matches your health goals.

The evidence, ingredient by ingredient Horny Goat Weed Maca Cowhage

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 3 of the 3 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 3 of 3.
  • General safety write-ups exist for 3 of 3.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Horny Goat Weed is generally well tolerated in short-term use, though side effects including dizziness, dry mouth, nosebleed, thirst, and vomiting have been reported. One rare case of respiratory arrest and another of heart rhythm problems were reported; quality and contents vary between products.

The safety data advises against use during pregnancy and while breastfeeding. Maca is generally well tolerated as a food, but long-term safety as a supplement has not been studied.

Fresh uncooked maca may cause stomach pain. Safety data is insufficient during pregnancy and breastfeeding.

Mucuna pruriens contains levodopa and should be used carefully with professional guidance. Most common side effects are diarrhea, flatulence, and mouth irritation when taken orally.

Nausea, abdominal bloating, and vomiting have been reported in clinical research at higher doses. Headaches and insomnia (in about 3% of patients at higher doses) have also been reported.

The safety data advises against use during pregnancy because of its dopamine effects, and against breastfeeding because levodopa can lower prolactin and reduce milk supply.

Side effects, ingredient by ingredient Horny Goat Weed Maca Cowhage

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?
  • 2 of the 3 matched ingredients can interact with medications — Horny Goat Weed, Cowhage.
  • The most serious interaction on file is rated Major.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; diabetes medications; Parkinson's medications.
  • For scale: 1,117 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 Formula 594, check with your pharmacist if you take methyldopa or any MAOI (an older class of antidepressant), or if you're already taking levodopa for any reason — these are Major-severity interactions. Also double-check if you take blood pressure medications, blood thinners or antiplatelet drugs, estrogen-based medications including birth control, diabetes drugs, antipsychotics, older-style antidepressants called tricyclic antidepressants, guanethidine, or drugs that are processed through your liver (many common medications are).

If you're scheduled for surgery and will receive anesthesia, let your anesthesiologist know you're taking this product.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with insufficient evidence for its stated purpose. Major medication interactions have been identified, and safety information is well characterized.

Formula 594 is a four-ingredient supplement with major interactions involving certain blood pressure drugs, antidepressants, and anesthetics — chiefly because of its Mucuna pruriens content. If you take any prescription medication or have cardiovascular or mood disorders, check your exact drugs with the tool on this page before starting.

This product is not recommended during pregnancy or breastfeeding. Talk with your pharmacist before use to make sure it's appropriate for you.

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

Assessment coverage: 3 of 4 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Jul 27, 2021.

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 Formula 594, straight from the product label.

Brand DC
Net contents 60 Capsule(s)
Market status Off market
Date entered into DSLD Jul 27, 2021
DSLD ID 245036
Product type Botanical
Supplement form Capsule
Dietary claims / uses All Other
Intended target group(s) Adult (18 - 50 Years), Women (not pregnant or lactating), Gluten 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 Formula 594 by DC, 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:
2 Capsule(s)
Maximum serving Sizes:
2 Capsule(s)
Servings per container
30
IngredientAmount% DV
Horny Goat Weed500 mg--
Maca250 mg--
Mucuna pruriens33.4 mg--
Polypodium vulgare ext.25 mg--

Other ingredients: Gelatin, Vegetable Cellulose, Vegetable 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

Directions: As a dietary supplement, take 2 capsules daily with a meal. For a more immediate response take 3 to 4 capsules 90 minutes before activity.

Precautions

Tamper Evident: Do not use this product if imprinted foil seal under cap is broken or missing.

Keep out of reach of children.

Caution: If you are pregnant or nursing do not take this product.

Formulation

Mfg. in an FDA Registered Facility using Good Manufacturing Practices (GMPs)

Conforms to USP <2091> for weight. Meets USP <2040> disintegration for maximum bioavailability.

Gluten free

Dynamic complex

Made in USA

Storage

Keep tightly closed. Store at room temperature: 59 degrees - 86 degrees F (15 degrees to 30 degrees C).

Seals/Symbols

Quali Pure

FDA Statement of Identity

Dietary Supplement

See for yourself

Formula 594 by DC label

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

What’s inside

The Ingredients in Formula 594 by DC

These are the 4 active ingredients this product is made of. Select any to open its full monograph.

Serving size2 Capsule(s) Dosage formCapsule Servings per container30 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.

Horny Goat Weed

Interacts with
963 drugs
500 mg per serving Form: Icariin

Horny goat weed (Epimedium) is a traditional Chinese herb most often marketed for low libido and erectile problems, but solid human evidence for these...

Horny Goat Weed monograph & interactions

Maca

No known
interactions
250 mg per serving Form: Glucosinolates

Maca is a nutrient-rich Andean root often used for energy, libido, and menopause symptoms. Early studies suggest it may modestly help sexual desire an...

Maca monograph & interactions

Mucuna pruriens

Interacts with
193 drugs
33.4 mg per serving Form: L-Dopa

Cowhage (Mucuna pruriens) is a tropical legume best known as a natural source of L-dopa, the compound the body turns into dopamine. It is most studied...

Mucuna pruriens monograph & interactions

Polypodium vulgare ext.

25 mg per serving

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

Interaction report

Formula 594 by DC Drug Interactions

Want to check YOUR meds against Formula 594?

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
1,116Drugs
17 Major 1,099 Moderate

Ingredients driving the most interactions

Each ingredient & the kinds of drugs it affects

For each ingredient in Formula 594 with known interactions, here are the types of medications they can affect. Open any type for the detail — or search your exact drug in the checker above.

Horny Goat Weed6 drug types · 963 drugs

Anticoagulant/Antiplatelet Drugs

Theoretically, horny goat weed might increase the risk of bleeding.
In vitro research and animal research shows that horny goat weed can inhibit platelet aggregation and thrombus formation. This effect has not been reported in humans.

Likelihood Possible Evidence D
Antihypertensive Drugs

Theoretically, horny goat weed might increase the risk of hypotension.
Laboratory research suggests that horny goat weed might have hypotensive effects. This effect has not been reported in humans.

Likelihood Possible Evidence D
Cytochrome P450 1A2 (Cyp1A2) Substrates

Theoretically, horny goat weed might increase the effects and side effects of CYP1A2 substrates.
In vitro, horny goat weed leaf extract inhibits CYP1A2. This effect has not been reported in humans.

Likelihood Possible Evidence D
Cytochrome P450 2B6 (Cyp2B6) Substrates

Theoretically, horny goat weed might increase the effects and side effects of CYP2B6 substrates.
In vitro, horny goat weed leaf extract inhibits CYP2B6. This effect has not been reported in humans.

Likelihood Possible Evidence D
Cytochrome P450 3A4 (Cyp3A4) Substrates

Theoretically, horny goat weed might increase the effects and side effects of CYP3A4 substrates.
In vitro, horny goat weed extract inhibits CYP3A4 and suppresses CYP3A4 mRNA expression. This effect has not been reported in humans.

Likelihood Possible Evidence D
Estrogens

Theoretically, concomitant use of horny goat weed with estrogens might increase their therapeutic and adverse effects.
In vitro evidence suggests that horny goat weed has estrogenic activity. In clinical research, horny goat weed has been shown to increase blood levels of estrogen in some females.

Likelihood Possible Evidence D

Mucuna pruriens8 drug types · 193 drugs

Levodopa

Concomitant use can increase the risk of levodopa-related adverse effects.
Cowhage contains levodopa. Some cowhage products have been standardized to contain 75-400 mg of levodopa per dose.

Likelihood Likely Evidence D
Methyldopa (Aldomet)

Theoretically, concomitant use of cowhage and methyldopa might increase the risk of hypotension.
Cowhage contains levodopa. Use of levodopa with methyldopa might cause additive hypotension. In addition, methyldopa may inhibit peripheral decarboxylation of levodopa and increase levodopa levels in the central nervous system; avoid using.

Likelihood Probable Evidence D
Monoamine Oxidase Inhibitors (Maois)

Theoretically, concomitant use of cowhage and non-selective MAOIs might increase the risk of hypertensive crisis.
Cowhage contains levodopa. Use of levodopa with non-selective MAOIs might cause hypertensive crisis. However, this interaction has not been reported with MAO-B selective inhibitors such as selegiline.

Likelihood Probable Evidence D
Anesthesia

Theoretically, concomitant use of cowhage and anesthesia might increase the risk of arrhythmias.
Cowhage contains levodopa. Use of levodopa with cyclopropane or halogenated hydrocarbon anesthesia has led to arrhythmias. Other anesthetics have not been implicated. Use other anesthetics in patients taking cowhage or tell patients to stop taking cowhage at least 2 weeks before surgery.

Likelihood Possible Evidence D
Antidiabetes Drugs

Theoretically, concomitant use of cowhage and antidiabetes drugs might increase the risk of hypoglycemia.
Animal research shows that cowhage might have hypoglycemic effects.

Likelihood Possible Evidence D
Antipsychotic Drugs

Theoretically, use of cowhage might decrease the clinical effects of antipsychotic drugs.
Cowhage contains levodopa. Use of levodopa might counteract the antidopaminergic effects of antipsychotic medications.

Likelihood Possible Evidence D
Guanethidine (Ismelin)

Theoretically, concomitant use of cowhage and guanethidine might increase the risk of hypotension.
Cowhage contains levodopa. Use of levodopa with guanethidine might cause additive hypotension; avoid using.

Likelihood Probable Evidence D
Tricyclic Antidepressants (Tcas)

Theoretically, use of TCAs might reduce the levels and clinical effects of cowhage.
Cowhage contains levodopa. Use of TCAs might reduce the absorption of levodopa. Some case reports describe patients that developed hypertension and dyskinesia when taking both levodopa and TCAs.

Likelihood Possible Evidence D
The maker

Brand information

Manufacturer and brand details for Formula 594, from the product label.

DC

See all DC products
Name
Dee Cee Laboratories, Inc.
Street Address
304 Dee Cee Rd.
City
White House
State
TN
ZipCode
37188
Pharmacist Counseling Corner

Formula 594 by DC: Common Questions

Does Formula 594 by DC interact with any medications?
Yes. Based on its ingredients, Formula 594 has a known interaction with 1,116 medications, including 17 rated major. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Formula 594 contains 4 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.
Can I take Formula 594 if I'm pregnant?
No. Horny Goat Weed and Mucuna pruriens both carry safety warnings against pregnancy use, and Maca also has insufficient data. Talk with your doctor or pharmacist before considering any supplement while pregnant.
Can I take it while breastfeeding?
No. Horny Goat Weed is advised against during breastfeeding, and Mucuna pruriens specifically can lower prolactin and reduce milk supply. Maca also lacks sufficient safety data. Avoid this product if you're nursing and speak with your doctor or pharmacist.
What is levodopa, and why is it in this product?
Levodopa is an active drug normally prescribed for Parkinson's disease — it works by boosting dopamine in the brain. It's included in this product (via Mucuna pruriens) because of that dopamine effect, but it also means this product carries serious interactions with certain medications and should be used only with professional guidance.
What are the most common side effects?
From Horny Goat Weed: dizziness, dry mouth, nosebleed, thirst, and vomiting. From Mucuna pruriens: diarrhea, flatulence, mouth irritation, and at higher doses, nausea, bloating, vomiting, headaches, and insomnia. Most people don't experience serious side effects, but quality varies between products.
Does this product actually work for sexual dysfunction?
The evidence supporting Horny Goat Weed and Maca for sexual dysfunction is insufficient — meaning we don't yet have reliable research showing they work. Talk with your doctor about what treatments have stronger evidence behind them.
Why does the product label say it interacts with over 1,000 medications?
Mucuna pruriens contains levodopa, and Horny Goat Weed can slow how your liver processes certain drugs. These two mechanisms together affect how your body handles a very large number of common medications — from heart drugs to pain relievers to antibiotics. That's why checking your exact prescriptions is so important.

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

Not sure if Formula 594 is safe with your meds?

Our pharmacists answer your medication & supplement questions — free.

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.

Formula 594 label
Sources

Sources & How We Checked

Formula 594'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 24 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.

Horny Goat Weed 11 references
  1. Cirigliano MD, Szapary PO. Horny goat weed for erectile dysfunction. Alt Med Alert 2001;4:19-22.
  2. Partin JF, Pushkin YR. Tachyarrhythmia and hypomania with horny goat weed. Psychosomatics 2004;45:536-7. PubMed
  3. De Naeyer A, Pocock V, Milligan S, De Keukeleire D. Estrogenic activity of a polyphenolic extract of the leaves of Epimedium brevicornum. Fitoterapia 2005;76:35-40. PubMed
  4. Zhang CZ, Wang SX, Zhang Y, et al. In vitro estrogenic activities of Chinese medicinal plants traditionally used for the management of menopausal symptoms. J Ethnopharmacol 2005;98:295-300. PubMed
  5. Yap SP, Shen P, Li J, et al. Molecular and pharmacodynamic properties of estrogenic extracts from the traditional Chinese medicinal herb, Epimedium. J Ethnopharmacol 2007;113:218-24. PubMed
  6. Yan, F. F., Liu, Y., Liu, Y. F., and Zhao, Y. X. Herba Epimedii water extract elevates estrogen level and improves lipid metabolism in postmenopausal women. Phytother.Res. 2008;22(9):1224-1228. PubMed
  7. Ramanathan VS, Mitropoulos E, Shlopov B, et al. An Enzyte'ing' case of acute hepatitis. J Clin Gastroenterol 2011;45(9):834-5. PubMed
  8. Zhong Q, Shi Z, Zhang L, et al. The potential of Epimedium koreanum Nakai for herb-drug interaction. J Pharm Pharmacol 2017;69(10):1398-408. doi: 10.1111/jphp.12773.
  9. Irfan M, Kwon TH, Lee DH, et al. Antiplatelet and Antithrombotic Effects of Epimedium koreanum Nakai. Evid Based Complement Alternat Med. Apr 2021;2021:7071987. PubMed
  10. Tan K, Yang W, Pang L, Hou F. Differences in clinical characteristics among 726 patients with Chinese herbal medicine- or Western medicine-induced liver injury. Medicine (Baltimore) 2022;101(32):e29909. PubMed
  11. Li K, Yu XH, Maskey AR, et al. Cytochrome P450 3A4 suppression by epimedium and active compound kaempferol leads to synergistic anti-inflammatory effect with corticosteroid. Front Pharmacol 2023;13:1042756. PubMed

See these in context on the Horny Goat Weed monograph →

Maca 1 reference
  1. Valerio, L. G., Jr. and Gonzales, G. F. Toxicological aspects of the South American herbs cat's claw (Uncaria tomentosa) and Maca (Lepidium meyenii) : a critical synopsis. Toxicol.Rev 2005;24(1):11-35. PubMed

See these in context on the Maca monograph →

Cowhage 12 references
  1. McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
  2. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
  3. Anon. Epidemiological notes and reports: Mucuna pruriens-associated pruritus--New Jersey. MMWR Morb Mortal Wkly Rep 1985;34:732-3.
  4. HP-200 in Parkinson's Disease study group. An alternative medicine treatment for Parkinson's disease: Results of a multicenter clinical trial. J Alt Comp Med 1995;1:249-55. DOI
  5. Infante ME, Perez AM, Simao MR, et al. Outbreak of acute toxic psychosis attributed to Mucuna pruriens. Lancet 1990;336:1129. PubMed
  6. Vaidya AB, Rajagopalan TG, Mankodi NA, et al. Treatment of Parkinson's disease with the cowhage plant-Mucuna pruriens Bak. Neurol India 1978;26:171-6.
  7. Vadivel V, Janardhanan K. Nutritional and anti-nutritional composition of velvet bean: an under-utilized food legume in south India. Int J Food Sci Nutr 2000;51:279-87. PubMed
  8. Akhtar MS, Qureshi AQ, Iqbal J. Antidiabetic evaluation of Mucuna pruriens, Linn seeds. J Pak Med Assoc 1990;40:147-50.
  9. Prakash, D., Niranjan, A., and Tewari, S. K. Some nutritional properties of the seeds of three Mucuna species. Int.J.Food Sci.Nutr. 2001;52(1):79-82.
  10. Vadivel, V. and Janardhanan, K. Nutritional and antinutritional characteristics of seven South Indian wild legumes. Plant Foods Hum.Nutr 2005;60(2):69-75. PubMed
  11. Creapure (Creatine Monohydrate). Toxicological Datasheet. Degussa BioActives. Available at: https://www.fda.gov/ohrms/DOCKETS/.../95s-0316-rpt0154-54-Ref-50-vol112.pdf.
  12. Pulikkalpura H, Kurup R, Mathew PJ, Baby S. Levodopa in Mucuna pruriens and its degradation. Sci Rep 2015;5:11078. PubMed

See these in context on the Cowhage 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

Keep exploring