Safety
BloodPril Side Effects: Interactions, Cautions and When to Call a Doctor
The BloodPril label lists no side effects, but its two arginine forms carry real cautions. L-arginine can add to blood pressure drugs, and with nitrates or sildenafil pressure can fall too low (Mayo Clinic, L-arginine). It is not advised after a recent heart attack. Ask your doctor before you start, keep taking your prescribed medicine, and stop the capsules if you feel faint.
Written by the BloodPril editorial teamUpdated
Side effects
What side effects can BloodPril cause?
No study has tracked side effects of BloodPril itself, so the honest answer comes from its ingredients.
The bottle lists no side effects, and no trial of the product has been published. The known risk comes from L-arginine, two of the three forms: blood pressure can drop too low when it is combined with certain drugs (Mayo Clinic, L-arginine).
The third form, L-citrulline DL-malate, is turned into arginine by the body, so its cautions follow arginine's. We could not open a citrulline safety study, so we print no citrulline side effect figures.
Signs to watch for in the first weeks
- Dizziness or lightheadedness when you stand up
- Feeling faint, or fainting
- Home cuff readings clearly below your usual range
- Any new symptom that started when the capsules did
Interactions
Which medicines interact with BloodPril?
Blood pressure drugs, nitrates and ED medicines top the list. Each row names its source.
| Medicine or situation | What can happen | What to do | Source |
|---|---|---|---|
| Blood pressure medicines (diuretics, ACE inhibitors, ARBs, calcium channel blockers, beta-blockers) | Arginine adds to the drug's effect; pressure may fall too low | Ask your prescriber first; keep every dose | (Mayo Clinic, L-arginine) (MedlinePlus, BP medicines) |
| Nitrates for chest pain | Blood pressure can drop too low | Do not combine without your doctor's OK | (Mayo Clinic, L-arginine) |
| ED medicines such as sildenafil | Blood pressure can drop too low | Tell the prescriber you take arginine | (Mayo Clinic, L-arginine) |
| Lisinopril | Same added effect; its label also flags potassium supplements and salt substitutes | Show the bottle; BloodPril prints no potassium | (MedlinePlus, Lisinopril) |
| A recent heart attack | L-arginine is not advised | Ask your cardiologist first | (Mayo Clinic, L-arginine) |
| Pregnant, nursing, under 18, or a known medical condition | Not studied in these groups | Consult a physician first | Label |
Not a complete list; a pharmacist can check every drug you take. More in the supplements and blood pressure medicines post.
Your medicines
Can BloodPril make blood pressure too low with my medicine?
Yes, that is the main risk. Mayo Clinic says L-arginine can add to the effect of blood pressure drugs (Mayo Clinic, L-arginine), so two things push in the same direction. MedlinePlus advises asking your provider whether to avoid supplements while on these drugs (MedlinePlus, BP medicines).
Never stop or change a dose on your own (MedlinePlus, BP medicines). If the two together feel like too much, the capsule is the part that goes.
Many ACE inhibitors end in "-pril"; lisinopril is one (MedlinePlus, Lisinopril). BloodPril contains no drug. At the pharmacy, call it "an arginine and citrulline supplement" so nobody mistakes it for a prescription.
Bring the bottle
The panel shows all three forms at a glance.
List every medicine
Include nitrates and ED drugs you take only now and then.
Agree on a stop rule
Ask which home readings mean you should stop and call.
Read the bottle
What does the BloodPril label caution say?
Three groups to check with a physician, plus a dose limit. No drug is named.
The caution reads, word for word: "CAUTION: Do not exceed recommended dose. Pregnant or nursing mothers, children under the age of 18 and individuals with a known medical condition should consult a physician before using this or any dietary supplement."
It does not mention nitrates, ED medicines or a past heart attack. The ingredient sources do, which is why the table above adds them.
- Dose: 1 capsule daily with an 8 oz glass of water, never more than 2.
- Other ingredients: Hydroxypropyl Methylcellulose (capsule), Microcrystalline Cellulose, Magnesium Stearate.
- Seal: skip any bottle whose safety seal is damaged or missing.
Every line of the panel is on the Supplement Facts page.
Quick check
Who should not take L-arginine?
People on blood pressure drugs, nitrates or ED medicines, anyone after a recent heart attack, and the groups the label names.
Those are the main reasons not to take L-arginine without a doctor's say-so (Mayo Clinic, L-arginine). Any "stop" or "doctor" result below means BloodPril waits for that conversation.
A checklist, not a diagnosis. See the L-arginine HCl profile for the full caution list.
Warning signs
When should you stop BloodPril and call a doctor?
Put the bottle aside and phone your doctor's office if any of these happen.
- You feel dizzy, lightheaded or faint, especially after a dose
- Home readings drop below the range your doctor gave you
- You are started on a nitrate, an ED medicine or a new blood pressure drug
- You become pregnant or start nursing
- You simply feel worse and cannot say why
You can put BloodPril down on any day; your prescription stays on your doctor's plan. Inside the 60-day window, the refund steps still apply.
Emergency
Which blood pressure signs mean you should call 911?
A reading higher than 180/120 is a crisis: seek care right away. Call 911 if that reading comes with chest pain, shortness of breath, weakness or vision changes (MedlinePlus, High blood pressure).
Never take an extra capsule to bring a high reading down. High blood pressure usually has no symptoms, so the cuff is your early warning.
Dose
Does taking more BloodPril raise the risk?
The label caps it at 2 capsules a day. More capsules mean more arginine working alongside your medicines.
| Daily amount | Whole blend | Arginine share |
|---|---|---|
| 1 capsule (label) | 500 mg | Not published |
| 2 capsules (label maximum) | 1,000 mg | Not published |
| Blood pressure trials, not BloodPril | 4 to 24 g of arginine | All of it (Dong et al., Am Heart J 2011) |
Even the maximum sits far below research amounts. That means less risk, and also little reason to expect a measured effect. A third capsule would not close the gap, and the label rules it out.
FAQ
BloodPril side effects and safety FAQ
What are the side effects of arginine?
The best-known risk is blood pressure falling too low, because arginine adds to blood pressure drugs, nitrates and sildenafil (Mayo Clinic, L-arginine). Mayo Clinic does not advise it after a recent heart attack. BloodPril's label lists no side effects, and no study of the product has tracked them.
Does L-citrulline cause constipation?
We found no source we could open that links L-citrulline to constipation, so we cannot say yes or no. If your digestion changes after you start BloodPril, stop the capsules and tell your doctor, and bring the bottle.
Are there side effects of taking high doses of citrulline?
BloodPril is not a high-dose product: its whole three-part blend is 500 mg per capsule. We could not open a citrulline safety study, so we print no high-dose figures. The body turns citrulline into arginine, so the arginine cautions apply (Mayo Clinic, L-arginine).
Is a nitric oxide supplement safe with low blood pressure?
Ask your doctor first. Arginine and citrulline are nitric oxide building blocks, and arginine adds to anything else that brings pressure down (Mayo Clinic, L-arginine). If your readings already run low, or you get dizzy when you stand, let a doctor decide.
Can you take L-arginine with sildenafil or nitrates?
Not without your doctor's approval. Mayo Clinic says combining L-arginine with nitrates or sildenafil can send blood pressure too low (Mayo Clinic, L-arginine). Tell every prescriber that you take BloodPril.
Is BloodPril safe after a heart attack?
L-arginine is not advised after a recent heart attack (Mayo Clinic, L-arginine), and two of BloodPril's three forms are arginine. Talk to your cardiologist before taking it, and keep every heart medicine on schedule.
What should I do if I feel dizzy after taking BloodPril?
Sit or lie down, then check your blood pressure if you have a cuff. Skip the next capsule and call your doctor's office. Leave your prescribed medicine as it is unless the doctor says otherwise.
Who wrote this
Written and reviewed by
Plain-language pages built from the label, the sales page and linked public health sources.
Last updated . Read our editorial standards and how we check reviews. This website is run by a U.S. shop that sells BloodPril, not by the manufacturer. We earn money when you buy through our order links.
Keep reading
More about BloodPril
Who it's for
A 5-question check, plus who might consider BloodPril, who should ask a doctor first and who should skip it.
Read more
Supplements and BP medicines
Blood pressure drug classes, the lisinopril potassium example, nitrates and ED medicine, and a checklist for your next visit.
Read moreSupplement Facts
The BloodPril label read line by line, including what a proprietary blend can and cannot tell you.
Read moreBloodPril U.S. shop
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