# MoodStack vs Synstax

The clearest difference is update cadence: MoodStack at every 4 days against Synstax's every 3 weeks. On price, ads, in-app purchases and monetization model there is nothing between them.

Both are free to download. MoodStack sells 11 in-app purchases, starting at $3.99 per 7 days and Synstax sells 3 in-app purchases, starting at $4.99 per month. Whichever you choose, the download price is not the number that matters.

MoodStack ships an update every 4 days, Synstax every 3 weeks. The most recent releases landed on October 1, 2026 and October 11, 2026 respectively.

## The numbers

| Metric | MoodStack | Synstax |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/synstax-interaction-checker/id6760453147/reviews)** |
| Number of ratings | — | **1** |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | **Every 4 days** | Every 3 weeks |
| Monetization | Freemium | Freemium |
| Size | 15 MB | 152 MB |
| Requires iOS | 18.0 | **17.0** |
| Devices | **iPhone, iPad** | iPhone |
| Age rating | 12+ | 12+ |
| Developer | [Martin Condet](https://appshunter.io/developer/1696467493) | [宁 丁](https://appshunter.io/developer/1848762948) |

## What reviewers say

### MoodStack

[App page](https://appshunter.io/ios/app/moodstack-supplement-truth/id6745878390)

This app analyzes supplements using AI to reveal their actual quality and effectiveness. It provides evidence-based recommendations for your health goals and audits your current supplement stack for potential issues and better alternatives.

**Highlights:** AI-powered supplement scanning, Quality score for products, Bioavailability and toxicity flags, Evidence-based symptom solver, Supplement stack auditing, Personalized alternative recommendations, Peptide library with sourced explainers

**Features:** macOS Compatibility

**In-app purchases (11)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Weekly Membership | $3.99 | per 7 days |
| Monthly Membership | $5.99 | per month |
| Weekly Membership | $9.99 | per 7 days |
| Monthly Membership | $9.99 | per month |
| MoodStack Pro — Yearly | $29.99 | per year |
| Yearly Membership | $47.99 | per year |
| Yearly Membership | $47.99 | per year |
| Yearly Membership | $49.90 | per year |
| Yearly Membership | $49.99 | per year |
| Yearly Membership | $69.99 | per year |
| Yearly Membership | $69.99 | per year |


### Synstax

[App page](https://appshunter.io/ios/app/synstax-interaction-checker/id6760453147)

This app helps you manage your supplement intake by checking for interactions between supplements and how your diet affects absorption. It features AI-powered label scanning, intake tracking, and personalized insights to optimize your routine.

**Highlights:** Supplement combination checker, Diet-supplement absorption insights, AI-powered label scanner, Smart intake tracking, AI analysis and chat, Personalized scheduling

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Synstax Pro | $4.99 | per month |
| Synstax Pro | $29.99 | per year |
| Synstax Pro Lifetime | $69.99 | one-time |


## Frequently asked questions

### Is MoodStack free?

MoodStack is free to download, with in-app purchases available.

### Is Synstax free?

Synstax is free to download, with in-app purchases available.

### Do MoodStack or Synstax have ads?

Neither MoodStack nor Synstax shows ads.

### Which is updated more often, MoodStack or Synstax?

MoodStack ships an update every 4 days, and Synstax every 3 weeks. Most recently, MoodStack was updated on October 1, 2026 and Synstax on October 11, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*