Maxentra is sold as a capsule supplement containing three listed amino-acid ingredients, all forms of L-arginine or L-citrulline; L-arginine is an amino acid with human research behind it, and the most common side effects WebMD lists for it are diarrhea and an upset stomach.
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Safety summary
- What is in it: a proprietary blend of 30 mg per capsule of L-arginine HCL, L-arginine alpha-ketoglutarate dihydrate and L-citrulline malate, plus organic white rice flour, a hydroxypropyl methylcellulose capsule and magnesium stearate.
- Effects reported for L-arginine: diarrhea and an upset stomach are the most common per WebMD. Cleveland Clinic lists bloating, nausea or vomiting and dizziness as possible.
- Medicines to ask about: blood-pressure medicines, nitrates, and the other medicines listed in the interaction table below.
- Not for use: the seller's label says the product is “Not for use for those under the age of 18 or pregnant or nursing mothers.”
- Ask a clinician first if you: have a medical condition or kidney concerns, or take any medication.
What is in Maxentra?
The seller's Supplement Facts panel shows a 30 mg proprietary blend of three ingredients. It does not break that 30 mg into amounts for each ingredient, so you cannot tell how much L-arginine or citrulline is in one capsule.
| Ingredient | Where it appears on the panel |
|---|---|
| L-Arginine HCL | Proprietary blend, 30 mg total per capsule |
| L-Arginine Alpha-Ketoglutarate Dihydrate | Proprietary blend, 30 mg total per capsule |
| L-Citrulline Malate | Proprietary blend, 30 mg total per capsule |
| Organic White Rice Flour | Other ingredients |
| Hydroxypropyl Methylcellulose (capsule) | Other ingredients |
| Magnesium Stearate | Other ingredients |
What does the research say about each ingredient?
L-arginine HCL
L-arginine is an amino acid that is naturally found in foods. WebMD's L-arginine overview says its benefits for most uses are not well defined. For athletic performance, WebMD reports that some studies show it does not help at all, while in some people who exercise in certain ways it may help by a small amount.
A mouse study of long-term L-arginine feeding notes that the effects of L-arginine on kidney function are controversial and that the safety of prolonged use, particularly in old age, is not clear. It was done in animals, so it does not show what happens in people taking this capsule.
L-arginine alpha-ketoglutarate
This is an arginine-based form, combined with alpha-ketoglutarate, so the L-arginine research above is the closest class research. This guide does not cite a human study for this exact form.
L-citrulline malate
This guide does not cite a human study for citrulline malate either. The side-effect detail in this guide is for L-arginine, so ask your pharmacist for citrulline's side-effect profile before you start.
What side effects are reported for L-arginine?
Cleveland Clinic's L-arginine guide says side effects are possible with L-arginine treatment and lists bloating, diarrhea, dizziness, and nausea or vomiting. WebMD says the most common side effects are diarrhea and an upset stomach.
| Effect reported for L-arginine | Where it is listed | Notes from the source |
|---|---|---|
| Diarrhea | Cleveland Clinic, WebMD | WebMD calls it one of the most common |
| Upset stomach | WebMD | Most common, per WebMD |
| Bloating | Cleveland Clinic | Listed as possible |
| Nausea or vomiting | Cleveland Clinic | Listed as possible |
| Dizziness | Cleveland Clinic | Listed as possible |
| Allergic reaction (hives, itching or rash) | Cleveland Clinic | Listed among the serious effects |
| Difficulty breathing or a tight feeling in the chest | Cleveland Clinic | Listed among the serious effects |
WebMD says these effects may be more likely at high doses. Taking the capsule exactly as the seller directs is the simplest step you control. If any effect bothers you, tell your clinician.
Which medicines interact with L-arginine?
Cleveland Clinic says: “Don't take l-arginine without first talking to your provider about medicines you currently take.” It also says L-arginine can cause interactions if you have certain health conditions. The seller's label says to consult a physician, especially if you take a medication.
| Medicine type | Examples named |
|---|---|
| ACE inhibitors | Benazepril, enalapril, lisinopril |
| Alpha-blockers | Doxazosin, prazosin |
| Angiotensin receptor blockers | Candesartan, irbesartan, losartan, valsartan |
| Beta-blockers | Atenolol, carvedilol, labetalol, metoprolol |
| Calcium channel blockers | Amlodipine, diltiazem, nifedipine, verapamil |
| Nitrates | Isosorbide, nitroglycerin |
| Propranolol and Hemangeol | Propranolol, Hemangeol |
| Vitamins or natural remedies | Fish oil |
Who should ask a clinician before taking Maxentra?
- Under 18, pregnant, or nursing: the seller's label says the product is “Not for use for those under the age of 18 or pregnant or nursing mothers.”
- Anyone taking blood-pressure medicine or nitrates: these are the medicine groups Cleveland Clinic names above.
- Anyone with kidney concerns, or planning long-term use: a mouse study of long-term L-arginine feeding notes the safety of prolonged use is not clear, particularly in old age. It was done in animals, so it does not show what happens in people.
- Anyone with a medical condition or allergies: the label asks you to consult a physician, and the ingredient list includes organic white rice flour.
- Anyone with surgery scheduled: tell the surgical team about the supplement before the procedure.
If you are looking at men's health options more broadly, see Men's Sexual and Prostate Health for an overview.
How do you start Maxentra safely?
The seller's directions are one capsule daily. The label also says “Do not exceed recommended dose,” to store the product in a cool, dry place, and to keep it out of reach of children. Do not use it if the safety seal is damaged or missing.
Cleveland Clinic says that in some cases the full effects of regular L-arginine treatment could take up to three months.
When to stop and get help: if you notice hives, itching or a rash, trouble breathing, or a tight feeling in your chest, stop using the capsule and get medical help right away. Cleveland Clinic says to reach out to your health care provider or visit the nearest emergency room immediately.
What does the research not settle?
- WebMD says: “The FDA has not reviewed L-arginine for safety and effectiveness.”
- WebMD also says: “The FDA has not tested L-arginine products to confirm that they contain the ingredients stated on their labels.”
- Ask the seller for a study citation for the blend before you order.
If you want a separate guide on what to watch when a supplement is taken for months, see mushroom supplements.
What does Maxentra cost?
Prices as of October 30, 2026; check the checkout for today's. The seller lists three bundles.
| Bundle | Supply | Price per bottle | Total shown | Shipping |
|---|---|---|---|---|
| Starter Package, 2 bottles | 60-day supply | $79 | $158 (listed beside $358) | Shipping added |
| Most Popular, 3 bottles | 90-day supply | $59 | $177 (listed beside $537) | Free US shipping |
| Best Value, 6 bottles | 180-day supply | $49 | $294 (listed beside $1074) | Free shipping |
Check today's price and bundle on the Product Page before you order.
How do refunds and returns work?
The seller's returns section sets these conditions for the 60-day money-back guarantee:
- Window: 60 days from the purchase date for a full refund.
- Contact first: contact support for return instructions before you send anything.
- Return everything: all bottles must come back, whether empty or not, to the returns address the seller lists.
- Include: a note with your full name, email address and order ID, and the packing slip.
- Shipping: you pay the return shipping costs, and those fees are non-refundable.
- After arrival: the refund is processed once the package is received and inspected, and you get an email confirmation.
Support contacts on the seller's page: phone +1 323-448-1373 and email support@getmaxentra.com.
Before you order
- Ask the seller for the amount of each ingredient in the 30 mg blend.
- Ask whether the capsules have third-party testing. WebMD notes that some supplements have been tested by third-party organizations to confirm their labeled ingredients.
- Take your full medicine list to your clinician or pharmacist before the first capsule, using the interaction table above.
By SterlingMedicalCenter.org Editorial Team
This article is for general information purposes only and does not constitute medical advice. Consult your doctor or qualified healthcare provider before making changes to your health routine.