Evidence-based·Last reviewed May 31, 2026·How we grade evidence

Isoleucyl-Prolyl-Proline

ProteinTripeptide

A casein-derived tripeptide (isoleucine-proline-proline) released when milk is fermented by Lactobacillus helveticus or hydrolyzed by specific proteases. Marketed (alongside VPP) as a 'natural ACE inhibitor' for mild hypertension. Asian trials showed ~5–7 mmHg systolic BP reduction; large Western RCTs found little or no effect. EFSA rejected the proposed BP health claim in 2008 and 2012.

Quick decision guide

May help most

Adults with mild hypertension who prefer a food-based adjunct to lifestyle change and accept a small, uncertain effect — not a substitute for evidence-based antihypertensive therapy.

Common dosing range

~3 mg/day IPP from fermented milk peptide drinks (AmealPeptide, Evolus brand); or 4.5–10 mg combined IPP+VPP/day in supplement products.

When to expect effects

4–8 weeks if any effect appears.

Watch out for

EFSA rejected the BP health claim. Modest effect in Asian trials has not consistently replicated in European or US trials. Lactose and milk-protein allergy carry over from the casein source.

Evidence snapshot

Blood pressure (pooled meta-analysis)Low (modest, uncertain)
Blood pressure (Western populations)Low (null effect)
EFSA-recognized health claimRejected

What is it

Isoleucyl-prolyl-proline (IPP) is a small tripeptide derived from milk casein, produced through enzymatic hydrolysis or bacterial fermentation. It is studied for its potential blood pressure-lowering effects through inhibition of angiotensin-converting enzyme (ACE).

Is it worth it for you?

Use this as a quick fit check, not a diagnosis.

Worth considering if…

You enjoy fermented milk products and want a low-risk food adjunct alongside diet, sodium reduction, and exercise
Your blood pressure is in the borderline/stage-1 range and you've decided to try food-based options before starting prescription therapy with your clinician
You're aware the effect, if any, is on the order of 1–3 mmHg in Western trials and you're calibrated for that

Probably skip if…

You have stage 2 hypertension or established cardiovascular disease — proven antihypertensives (ACE inhibitors, ARBs, CCBs, thiazides) lower BP 10+ mmHg with hard-outcome evidence
You're allergic to milk proteins or strictly avoiding dairy
You're hoping for a meaningful effect based on the Japanese trials — Western replications have not held up
You're already at goal BP on prescription therapy
You're looking for an EFSA- or FDA-recognized food health claim — neither approved one for lactotripeptides

Evidence at a glance

Mild hypertension / blood pressure lowering

Limited Evidence
Effect
Pooled meta-analysis: systolic ~−4 mmHg, diastolic ~−2 mmHg; null in large Western trials; EFSA-rejected claim
Best fit
Mild hypertensives looking for a food adjunct on top of lifestyle change
Time
4–8 weeks

Evidence for 1 use

AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.

Mild hypertension / blood pressure lowering

Supplement benefit
Limited Evidence

Pooled meta-analyses (Cicero 2011, Cicero 2013, Xu 2008) of 18–33 RCTs show small reductions in systolic (~−4 mmHg) and diastolic (~−2 mmHg) BP versus placebo, with effects much larger in Asian than in European populations and substantial trial-level heterogeneity. The large Dutch Engberink 2008 trial (n=275) found no BP effect. EFSA reviewed the totality of evidence twice (2008, 2012) and rejected the proposed Article 13.1 health claim. The most defensible interpretation: a small effect may exist, particularly at higher doses in Asian populations, but it has not been reliably demonstrated in Western adults and is not large enough to substitute for evidence-based antihypertensive therapy.

Effect size
Pooled meta-analysis: systolic ~−4 mmHg, diastolic ~−2 mmHg; null in large Western trials; EFSA-rejected claim
Time to effect
4–8 weeks
Best fit
Mild hypertensives looking for a food adjunct on top of lifestyle change
Less likely
Stage 2 hypertension; established cardiovascular disease; people already at goal BP; Western adults expecting an effect similar to the Asian trial body

Bottom line: Small, uncertain effect that EFSA does not consider proven. Not a substitute for evidence-based BP therapy in anyone needing meaningful reduction.

Evidence is mixed

Asian RCTs report 5–7 mmHg systolic reductions; the large Western Engberink 2008 RCT (n=275) found no effect, and EFSA rejected the BP health claim in 2008 and 2012. Heterogeneity and publication bias are real concerns in the meta-analyses.

SourceEngberink et al., 2008 — American Journal of Clinical Nutrition· conflictingEFSA NDA Panel, 2012 — EFSA Journal· conflictingCicero et al., 2013 — Pharmacological Research
SourceCicero et al., 2011 — American Journal of HypertensionCicero et al., 2013 — Pharmacological ResearchXu et al., 2008 — Hypertension ResearchEngberink et al., 2008 — American Journal of Clinical NutritionMizuno et al., 2005 — Journal of HypertensionEFSA NDA Panel, 2012 — EFSA Journal

How it works

IPP is an ACE inhibitor - it blocks the enzyme that converts angiotensin I to angiotensin II, a hormone that raises blood pressure. This is the same mechanism as prescription ACE inhibitors like lisinopril, though IPP is far less potent. Clinical studies of IPP-containing milk peptide products (often marketed as AmealPeptide or Calpis fermented milk drinks) have shown modest blood pressure reductions, typically 3-6 mmHg systolic and 1-3 mmHg diastolic in people with mild hypertension. Some meta-analyses are positive; others find no effect.

How to take it

1. Typical dose
• Fermented milk peptide drinks (AmealPeptide, Evolus brand): ~3 mg IPP + ~2 mg VPP per daily serving • Supplement capsules with concentrated lactotripeptides: 4.5–10 mg combined IPP+VPP/day • No regulator-recognized dose; EFSA rejected the BP health claim
2. Higher studied dose
Up to ~15 mg combined IPP+VPP/day studied; higher doses don't reliably add benefit. The Cicero 2013 meta-analysis suggested slightly larger effect above 3 mg/day per peptide.
3. Timing
Daily, time of day does not appear to matter for the chronic BP endpoint. Consistency over weeks matters more than per-dose timing.
4. With food
With or without food.
5. Split dosing
Single daily serving in most trials. Split dosing has not been shown to add benefit.
6. How long to try
4–8 weeks before judging effect on home BP averages. If no measurable change after 8 weeks at recommended dose, the effect is unlikely to appear.

What to track

Home BP readings (morning + evening averages) at baseline and weekly
Dietary sodium, alcohol, weight — the bigger movers in mild hypertension
Lactose / dairy tolerance if using milk peptide drinks
Other supplements and OTC drugs that affect BP (NSAIDs, decongestants, licorice)

Bottom line: If used at all: 3–10 mg combined IPP+VPP daily for 8 weeks alongside diet, exercise, sodium reduction. Don't expect more than 1–3 mmHg from this alone.

3 commercial forms

Compare the main delivery options and what they’re best suited for.

AmealPeptide (Calpis / Asahi Calpis Wellness)

Original brand

Japanese commercial lactotripeptide product, casein hydrolysate standardized for IPP and VPP content. Forms include the Ameal BP fermented milk drink and capsule versions. Most positive Asian BP trials used this product or close analogs.

Food-matrix delivery; oral bioavailability of intact peptides is partial.

Evolus (Valio, Finland)

European fermented milk

Fermented dairy drink containing IPP and VPP generated by L. helveticus LBK-16H. Marketed in Finland for mild hypertension; later European trials and EFSA review concluded effect not robust in non-Asian populations.

Same delivery format as AmealPeptide.

Casein hydrolysate capsules / powders

Concentrated supplement

Standardized casein hydrolysate (sometimes additionally fortified with synthetic IPP and VPP) in capsule or powder form, with lactose typically removed. Convenient daily dose; same evidence base as fermented milk.

Concentrated delivery, lactose-removed; identical peptide bioavailability concerns as food matrix.

Safety

Know the common side effects, key cautions, and who should avoid it.

Common side effects

GI upset (uncommon)lactose intolerance symptoms if the source product contains lactose

Serious risks

  • Milk-protein allergic reactions in cow's milk protein–allergic individuals — IPP is a casein-derived peptide; trace casein protein may co-occur in some products.

  • Additive BP-lowering with prescription antihypertensives — generally a non-issue at the modest effect size observed, but combine with monitoring.

    SourceCicero et al., 2013 — Pharmacological Research

Who should avoid it

  • People with cow's milk protein allergy — casein source.
  • People with severe lactose intolerance, if the source product is a lactose-containing fermented milk drink. Concentrated peptide capsules typically are lactose-free.
  • Anyone with stage 2 hypertension or established cardiovascular disease who should be on proven antihypertensive therapy — don't substitute lactotripeptides.

Pregnancy & breastfeeding

Fermented milk products and milk-derived peptides at culinary or normal supplement doses are considered safe in pregnancy and breastfeeding. No specific RCT data in pregnancy; effect on BP, if any, is small and unlikely to be clinically meaningful in this population.

Bottom line: Generally safe at studied doses. Main caveats are dairy-allergen carryover and the broader 'don't use this as primary BP therapy' point.

Interactions

ACE inhibitors (lisinopril, enalapril, ramipril)Minor

Mechanistically related — both classes inhibit ACE. Additive effect is small at typical lactotripeptide doses; monitor BP if combining.

SourceFitzGerald et al., 2004 — Journal of Nutrition
other antihypertensives (ARBs, calcium channel blockers, thiazides, beta-blockers)Minor

Theoretical additive BP-lowering effect; clinically modest. Monitor home BP when starting or stopping.

no significant CYP or transporter interactions documentedMinor

Lactotripeptides do not have well-characterized cytochrome P450 or drug-transporter interactions at supplement doses.

Food sources

Fermented milk drinks (AmealPeptide, Evolus, related products)

Amount
~3 mg IPP per serving in commercial products
%DV
—

Traditional aged cheeses (Gouda, Cheddar, Parmesan)

Amount
Small amounts of IPP and VPP form during ripening; not commercially standardized
%DV
—

Plain yogurt and kefir

Amount
Trace IPP/VPP depending on starter culture; far below trial doses
%DV
—

Choosing a product

What to look for on the label — and what to be skeptical of.

Look for…

Combined IPP + VPP content stated in mg per serving (not just 'lactotripeptide blend')
Source clarified — fermented milk (L. helveticus) or enzymatically hydrolyzed casein
Third-party tested for milk protein and contaminants
Lactose-free option if dairy intolerance applies
Single-ingredient product if you want to evaluate the effect cleanly

Be skeptical of…

'Natural ACE inhibitor — replaces prescription BP medication' — false; effect is much smaller than prescription therapy
'EFSA-approved blood pressure benefit' — false; EFSA rejected the claim
'Proven to prevent heart attack or stroke' — no hard-outcome trial evidence
'Safe to combine with any other BP product without monitoring' — always monitor BP when changing antihypertensive regimens
Mega-dose marketing (>30 mg/day) for added cardiovascular benefit — no dose-response evidence supports it

Frequently asked questions

Can IPP replace blood pressure medication?⌄

No. The effect is much smaller than prescription medications. It may provide modest support but should not replace prescribed treatment.

References by claim

Mild hypertension / blood pressure lowering

Cicero et al., 2011 — American Journal of Hypertension (2011) link

Cicero et al., 2013 — Pharmacological Research (2013) link

Xu et al., 2008 — Hypertension Research (2008) link

Engberink et al., 2008 — American Journal of Clinical Nutrition (2008) link

EFSA NDA Panel, 2012 — EFSA Journal (2012) link

Mizuno et al., 2005 — Journal of Hypertension (2005) link

Interaction: ACE inhibitors (lisinopril, enalapril, ramipril)

FitzGerald et al., 2004 — Journal of Nutrition (2004) link

Track Isoleucyl-Prolyl-Proline with Pilora

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Evidence-based·Last reviewed May 31, 2026·Evidence current as of May 31, 2026·How we grade evidence

Disclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you’re pregnant, breastfeeding, on medications, or managing a chronic condition.