# ContrastRx vs SIR Guidelines

The clearest difference is rating: SIR Guidelines at 5.0 against ContrastRx's 4.4. On price, ratings volume, update cadence and ads there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

SIR Guidelines holds the better App Store score, 5.0 against 4.4. Both are backed by a comparable volume of ratings — 9 and 23 respectively.

Both ship on a similar rhythm, roughly every 3 weeks. The most recent releases landed on October 13, 2026 and October 3, 2026 respectively.

## The numbers

| Metric | ContrastRx | SIR Guidelines |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.4 (9 ratings)](https://appshunter.io/ios/app/contrastrx/id619478666/reviews) | **[5.0 (23 ratings)](https://appshunter.io/ios/app/sir-guidelines/id1552455529/reviews)** |
| Number of ratings | 9 | **23** |
| Positive reviews | 50.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 3 weeks | Every 3 weeks |
| Monetization | Free | Free |
| Size | 9 MB | 28 MB |
| Requires iOS | 16.6 | **15.1** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 17+ | 12+ |
| Developer | [Mayo Clinic](https://appshunter.io/developer/350350016) | [Society of Interventional Radiology](https://appshunter.io/developer/508819578) |

## What reviewers say

### ContrastRx

[App page](https://appshunter.io/ios/app/contrastrx/id619478666)

Provides quick access to treatment regimens for life-threatening reactions to radiographic contrast agents. Includes clinical descriptions, visual examples, and treatment protocols, along with helpful calculators and information on nephrogenic systemic fibrosis.

**Highlights:** Treatment regimens for contrast reactions, Clinical descriptions and pictorial examples, eGFR calculator, Pediatric dose calculator, Steroid pretreatment regimens, Nephrogenic systemic fibrosis overview

**Features:** Vision Pro support

**In-app purchases:** none


### SIR Guidelines

[App page](https://appshunter.io/ios/app/sir-guidelines/id1552455529)

Access evidence-based recommendations and tools for healthcare professionals. Features an interactive calculator for scenario-specific anticoagulation and antibiotic advice, simplifying clinical decision-making at the point of care.

**Highlights:** Access published guidelines and statements, Interactive periprocedural recommendation calculator, Scenario-specific anticoagulation and antibiotic recommendations, Tailored recommendations based on patient and procedural risk, Clinical Practice Guidelines for IVC Filters, Continual updates with new guidelines and tools

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is ContrastRx free?

ContrastRx is free to download, with no in-app purchases.

### Is SIR Guidelines free?

SIR Guidelines is free to download, with no in-app purchases.

### Which has better reviews, ContrastRx or SIR Guidelines?

SIR Guidelines is rated higher. ContrastRx averages 4.4 out of 5 from 9 ratings, while SIR Guidelines averages 5.0 from 23 ratings.

### Do ContrastRx or SIR Guidelines have ads?

Neither ContrastRx nor SIR Guidelines shows ads.

### Which is updated more often, ContrastRx or SIR Guidelines?

ContrastRx ships an update every 3 weeks, and SIR Guidelines every 3 weeks. Most recently, ContrastRx was updated on October 13, 2026 and SIR Guidelines on October 3, 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.*