Zest vs Prove It
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Zest
Discover your body's internal age and receive personalized insights to slow your aging rate. This app uses at-home tests and machine learning to analyze health metrics like cardiovascular fitness and cognitive function, providing tailored recommendations for improvement.
- Measure Functional Age
- At-home health testing
- Personalized health insights
- Machine learning analysis
- Tailored recommendations
- Track aging metrics
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Ever wondered how old your body actually is on the INSIDE? Discover your Functional Age with Zest. For the first time in history, we have the tools to address aging at its core, and the science to help you to slow your rate of aging. A big part of this is tracking your body’s age on the inside and working to improve your metrics – which is where Zest comes in. Our app and simple at-home test dive deeply into your health, measuring everything from cardiovascular fitness, metabolic health, cognitive function and hormonal health. We use cutting-edge machine learning technology to analyze this data and give you an incredibly accurate measure of your Functional Age (your body’s age on the inside) which you can track and improve over time. Unlike chronological age, which simply counts years, functional age takes a holistic approach and looks at all of your body systems. How it works: 1. Unbox your at-home test: A simple finger prick and a few quick questions to get started. 2. Mail it back: We'll analyze your blood and digital biomarkers to reveal your Functional Age. 3. Results in-App: Dive into personalized insights about your body's performance. 4. Optimize your health: Get tailored recommendations to keep improving your functional age over time. Zest was built by a team of medical doctors, longevity scientists and researchers, and backed up by 100+ clinical trials. We are constantly updating and evaluating our recommendations to ensure we are consistent with the latest research. Are you ready to feel younger for longer? Let's redefine aging together. This product is not intended for diagnostic or treatment purposes and does not constitute healthcare advice. It is designed for healthy individuals to better understand their bodies and avoid future diseases. If you are concerned about any of your results in this app please contact your healthcare provider.
Prove It
Empower your supplement choices with science-backed reviews. Instantly scan barcodes or search our database to understand ingredient efficacy, safety, and research quality. Make informed decisions about your health investments.
- Evidence-based analysis
- Barcode scanning
- Extensive supplement database
- Ingredient efficacy and safety
- Research quality assessment
- Informed decision making
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Take control of your supplement choices with comprehensive, science-based reviews in seconds. Whether you're at the store or researching at home, our app helps you: - Access evidence-based analysis of supplement efficacy and safety - Instantly scan product barcodes to get detailed reviews - Search our extensive database of supplements - Understand the science behind ingredient claims - Make informed decisions about your health investments Every review is grounded in scientific research, helping you understand: - What the research actually says about effectiveness - Known safety considerations and interactions - Recommended dosages based on clinical studies - Quality of available evidence Stop wondering about supplement claims and start making evidence-based decisions for your health. MEDICAL DISCLAIMER: This app is for educational and informational purposes only. It is not intended to provide medical advice, diagnosis, or treatment recommendations. The information provided should not be used as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified healthcare provider with any questions you may have regarding supplements, a medical condition, or treatment, and never disregard professional medical advice or delay in seeking it because of something you have read in this app. Decisions about supplement use should be made in consultation with your healthcare providers, taking into account your individual health circumstances. Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Screenshots
Verdict
The clearest difference is rating: Zest at 5.0 against Prove It's 4.4. Zest also leads on in-app purchases (none vs 10) and ads (none vs shown). Prove It's advantage is ratings volume (16K vs 1) and update cadence (every 6 days vs every 3 weeks). On price, device support and iOS requirement there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Prove It sells 10 in-app purchases, starting at $29.99 per year. Zest asks for nothing beyond the download.
Zest holds the better App Store score, 5.0 against 4.4. That said, the two scores are not equally well evidenced: Prove It has 16K ratings behind it against 1, so its average is the more settled of the two.
Zest ships an update every 3 weeks, Prove It every 6 days. The most recent releases landed on October 30, 2026 and November 7, 2026 respectively.
| Parameter | Zest | Prove It |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (1 ratings) — better | 4.4 (16K ratings) |
| Positive reviews | — | 9.1% of reviews |
| Number of ratings | 1 | 16K — better |
| Update frequency | Every 3 weeks | Every 6 days — better |
| Ads | No — better | Yes |
| In-app purchases | No — better | Yes |
| Monetization | Free — better | Free with in-app purchases |
| Devices | iPhone, iPod | iPhone, iPad, iPod — better |
| Requires iOS | 16 | 15.1 — better |
| Further details — not scored | ||
| Size | 23 MB | 132 MB |
| Age rating | 17+ | 4+ |
| Developer | Zest Longevity LTD | Control. Alt. Delete. LLC |
Customer experience
Zest
Prove It
Bugs and requests
Zest
Not enough reviews yet to summarise bugs or requests.
Prove It
Reported bugs
2 issues- Scanning errors
- Incompatibility with some supplements
Requested features
2 requests- Ability to manually add supplements
- Reduce subscription cost
In-app purchases
Zest
No in-app purchases
Prove It
- Food and Skincare Health Plan$29.991 Year
- Prove It Quarterly$29.993 Months
- Yearly Subscription$29.991 Year
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- Pro Subscription$32.493 Months
- Yearly Subscription$35.901 Year
- Prove It Quarterly$39.993 Months
- Yearly Subscription$39.991 Year
- Yearly Subscription$47.901 Year
- yearly subscription$69.991 Year
- yearly subscription$99.991 Year









