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L-Citrulline Side Effects: What Studies Reported
L-citrulline side effects reported so far are mostly stomach upset. In one NIH-cited study, 6 of 41 weightlifters had stomach discomfort after 8 grams of citrulline malate. Up to 6 grams a day for four weeks showed no adverse effects. A Melonex capsule holds at most 500 mg in its citrulline line.
Written by the Melonex numbers deskUpdated · 4 min read
01What studies saw
What side effects did L-citrulline studies report?
The most common L-citrulline side effect in the sources we read is an upset stomach.
WebMD names upset stomach as the most common effect. It adds that pregnancy and breastfeeding effects are not known (WebMD, L-citrulline).
The NIH fact sheet gives the sharpest number. After 8 grams of citrulline malate, 6 of 41 weightlifters reported stomach discomfort. That is about 15% of the group (NIH ODS, Supplements for Exercise).
The same sheet says up to 6 grams a day for 4 weeks reported no adverse effects. It says long-term safety has not been adequately assessed (NIH ODS, Supplements for Exercise).
| Dose | What was reported |
|---|---|
| Up to 6 g a day, 4 weeks | No adverse effects reported |
| 8 g citrulline malate, once | Stomach discomfort in 6 of 41 lifters |
| Long term | Not adequately assessed |
02Capsule scale
Could a Melonex capsule cause those effects?
A capsule's citrulline line holds at most 500 mg, which is 6% of the 8 g dose that upset some lifters.
Two capsules reach at most 1,000 mg, or 13% of 8 g. These are ceilings for the whole salt, so the citrulline itself is lower.
Lower dose does not mean zero risk. Anyone can react to any supplement, and the blend also holds two arginine lines. Their effects are covered in our post on arginine stomach side effects.
1 capsule a day
- L-Citrulline DL-Malate≤500 mg
- L-Arginine (Alpha-Ketoglutarate dihydrate)≤250 mg
- L-Arginine HCL≤167 mg
- Whole blend500 mg
- Water
- 8 oz with the capsule
- One bottle lasts
- 60 days
- Label
- The suggested use
2 capsules a day
- L-Citrulline DL-Malate≤1,000 mg
- L-Arginine (Alpha-Ketoglutarate dihydrate)≤500 mg
- L-Arginine HCL≤333 mg
- Whole blend1,000 mg
- Water
- 16 oz with the capsules
- One bottle lasts
- 30 days
- Label
- The most the label allows
Ceilings from the label order (place k holds at most 500/k mg) (21 CFR 101.36 (proprietary blends)). The label: "As a dietary supplement, take one (1) capsule daily with an 8 oz. glass of water. May take up to two (2) capsules daily."
03Medicines
Does L-citrulline interact with medicines?
Yes: WebMD lists blood pressure medicines, nitrates and ED drugs as interaction risks for L-citrulline.
WebMD says these interactions are not fully understood (WebMD, L-citrulline). Low pressure is the main worry. It means a reading below 90/60, with dizziness, fainting, blurry vision or weakness (NHLBI, Low blood pressure).
If you take a blood pressure medicine, a nitrate for chest pain or an ED drug, ask your doctor or pharmacist before you add any citrulline product. Keep taking your prescribed medicine.
That is why a supplement list matters as much as a medicine list. A pharmacist can check both in a few minutes.
- Bring the bottle or a photo of the label to the visit.
- Name every supplement, not only this one.
- Report dizziness right away.
04Who waits
Who should check with a doctor first?
Pregnant or nursing mothers, anyone under 18 and anyone with a known medical condition should consult a physician first, says the Melonex label.
That is the label's own caution. The research adds a gap: no pregnancy or nursing data are known for citrulline (WebMD, L-citrulline).
Also stop and seek care for signs of an allergic reaction, such as hives or swelling. The sources we read do not cover that, so it is general safety advice, not a finding.
Read the who-should-take guide before you order. It sets out the cases where a supplement is a poor fit.
05Decide
What does this mean if you plan to try Melonex?
It means a low risk of stomach effects at capsule size, an unknown long-term picture and a few clear reasons to ask first.
Start with one capsule and a full glass of water, as the label says. Log how you feel for 30 days. The side effects and interactions page has the full medicine table.
Refunds need 30 days of use, sealed bottles and a 20% restocking fee, so decide with that in mind. The 3- and 6-bottle packs ship free per the seller's order page.
Prices listed on the seller's order page; confirm at checkout. The 2-bottle kit costs $158, with $9.99 shipping. Ask your doctor about your medicines first. 60-day money-back guarantee per the seller.
Melonex is not a treatment; it is a dietary supplement. Ask your doctor or pharmacist first if you take blood-pressure medicine, nitrates for chest pain, an erectile-dysfunction drug such as sildenafil or tadalafil, a potassium-sparing diuretic (amiloride, spironolactone, triamterene), a blood thinner, or diabetes medicine, or if you have had a recent heart attack. Arginine and citrulline can add to these. Keep taking prescribed medicine. See side effects and interactions.
06FAQ
Melonex questions people ask
Can L-citrulline upset your stomach?
It can. WebMD calls upset stomach the most common side effect (WebMD, L-citrulline). In one study cited by NIH, 6 of 41 weightlifters had stomach discomfort after 8 grams of citrulline malate. A Melonex capsule line is at most 500 mg.
Is L-citrulline safe long term?
Nobody knows yet. NIH says long-term safety of citrulline has not been adequately assessed (NIH ODS, Supplements for Exercise). The best-documented stretch is up to 6 grams a day for 4 weeks with no adverse effects reported.
Can L-citrulline cause low blood pressure?
It may add to blood pressure medicines and nitrates, which can push pressure down too far (WebMD, L-citrulline). Low is below 90/60. Dizziness or fainting is a reason to call your doctor, and you should keep taking prescribed medicine.
Is L-citrulline safe while nursing?
Effects during pregnancy and breastfeeding are not known (WebMD, L-citrulline). The Melonex label asks pregnant or nursing mothers to consult a physician before use. Do not start it without that conversation.
07Who wrote this
Written and reviewed by
Pages built from the label, the seller's materials and linked NIH, FDA, CDC, AHA, FTC and peer-reviewed sources.
Last updated . Read how we write and how we check reviews. This website is run by Melonexheart, which describes itself as a U.S. authorized Melonex merchant. It is not the manufacturer or the label's distributor, and we cannot independently verify the 'authorized' status. We are paid when you buy through our order links.
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Show the bottle to your doctor or pharmacist first, then pick a pack. Six bottles cost the least per bottle, and the seller lists a 60-day money-back guarantee on every pack.
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