# Mosby's Drug Reference vs COSA

The clearest difference is rating: Mosby's Drug Reference at 4.6 against COSA's 3.7. Mosby's Drug Reference also leads on ads (none vs shown) and ratings volume (235 vs 3). COSA's advantage is in-app purchases (none vs 1) and update cadence (every 3 months vs every 9 months). On price there is nothing between them.

Both are free to download. Mosby's Drug Reference sells 1 in-app purchase, starting at $45.99 per year. COSA asks for nothing beyond the download.

Mosby's Drug Reference holds the better App Store score, 4.6 against 3.7. That said, the two scores are not equally well evidenced: Mosby's Drug Reference has 235 ratings behind it against 3, so its average is the more settled of the two.

Mosby's Drug Reference ships an update every 9 months, COSA every 3 months. The most recent releases landed on September 24, 2026 and September 10, 2026 respectively.

## The numbers

| Metric | Mosby's Drug Reference | COSA |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.6 (235 ratings)](https://appshunter.io/ios/app/mosbys-drug-reference/id959042883/reviews)** | [3.7 (3 ratings)](https://appshunter.io/ios/app/cosa-medication-information/id1626158440/reviews) |
| Number of ratings | **235** | 3 |
| Positive reviews | 31.8% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | **No** | Yes |
| Update frequency | Every 9 months | **Every 3 months** |
| Monetization | Free with in-app purchases | **Ad-supported** |
| Size | 9 MB | 28 MB |
| Requires iOS | 15.0 | **11.0** |
| Devices | **iPhone, iPad, iPod, Mac** | iPhone, iPod |
| Age rating | 17+ | 4+ |
| Developer | [Unbound Medicine, Inc.](https://appshunter.io/developer/300420400) | [MEDICAL EDUCATION RESOURCES, LLC](https://appshunter.io/developer/1561046509) |

## What reviewers say

### Mosby's Drug Reference

[App page](https://appshunter.io/ios/app/mosbys-drug-reference/id959042883)

This app provides healthcare professionals with comprehensive drug information, including actions, usage, dosage, interactions, and side effects. It emphasizes patient safety with Black Box Warnings, Safety Alerts, and information on life-threatening side effects. Features include custom notes, highlights, and quick search functionality.

**Highlights:** Over 5,000 drug listings, Black Box Warnings and Safety Alerts, Drug action, usage, dosage, interactions, side effects, Custom notes and highlights, Full text search, Appendix of recent FDA-approvals

**Features:** Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Mosby's Drug Reference | $45.99 | per year |


### COSA

[App page](https://appshunter.io/ios/app/cosa-medication-information/id1626158440)

Access essential drug information and advanced patient resources. This app provides a portion of licensed drug data from a leading healthcare information provider, based on industry-standard databases.

**Highlights:** Essential drug information, Advanced patient resources, Licensed drug data, Industry-standard databases, Physician-focused resources

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Mosby's Drug Reference free?

Mosby's Drug Reference is free to download, with in-app purchases available.

### Is COSA free?

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

### Which has better reviews, Mosby's Drug Reference or COSA?

Mosby's Drug Reference is rated higher. Mosby's Drug Reference averages 4.6 out of 5 from 235 ratings, while COSA averages 3.7 from 3 ratings.

### Do Mosby's Drug Reference or COSA have ads?

COSA shows ads; Mosby's Drug Reference does not.

### Which is updated more often, Mosby's Drug Reference or COSA?

Mosby's Drug Reference ships an update every 9 months, and COSA every 3 months. Most recently, Mosby's Drug Reference was updated on September 24, 2026 and COSA on September 10, 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.*