# 瘦着呢 vs Synstax

The clearest difference is update cadence: 瘦着呢 at every 8 days against Synstax's every 3 weeks. On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. 瘦着呢 sells 3 in-app purchases, starting at $1.99 per month 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.

瘦着呢 ships an update every 8 days, Synstax every 3 weeks. Both last shipped on October 31, 2026.

## The numbers

| Metric | 瘦着呢 | 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 8 days** | Every 3 weeks |
| Monetization | — | Freemium |
| Size | 7 MB | 151 MB |
| Requires iOS | **16.6** | 17.0 |
| Devices | iPhone | iPhone |
| Age rating | 12+ | 12+ |
| Developer | [雨 李](https://appshunter.io/developer/1619366507) | [宁 丁](https://appshunter.io/developer/1848762948) |

## What reviewers say

### 瘦着呢

[App page](https://appshunter.io/ios/app/id6758323337)

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 瘦着呢全能版 · 月度 | $1.99 | per month |
| 瘦着呢全能版 · 年度 | $12.99 | per year |
| 瘦着呢全能版 · 月度 | $7.99 | one-time |


### Synstax

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

This app helps you manage supplement intake by checking for harmful combinations, analyzing food interactions, and tracking dosages. It features an AI-powered label scanner to extract product information and provides smart scheduling for your routine. Get personalized insights and guidance for your wellness journey.

**Highlights:** Supplement combination checker, Food and supplement interaction analysis, Intake and dosage tracking, AI label scanner, AI analysis and chat, Smart 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 瘦着呢 free?

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

### Is Synstax free?

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

### Do 瘦着呢 or Synstax have ads?

Neither 瘦着呢 nor Synstax shows ads.

### Which is updated more often, 瘦着呢 or Synstax?

瘦着呢 ships an update every 8 days, and Synstax every 3 weeks. Most recently, 瘦着呢 was updated on October 31, 2026 and Synstax on October 31, 2026.

---

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