WeightCompare vs Monj: Which UK Price Comparison Site Is More Accurate?

If you have searched for Mounjaro prices in the UK, you have probably come across two comparison sites: WeightCompare.co.uk and Monj.co.uk. Both claim to help you find the cheapest Mounjaro from GPhC-registered pharmacies. But they work very differently, and those differences matter when you are spending £130–£375 per month on medication. We built WeightCompare because we felt existing comparison tools were not giving patients the full picture. Here is an honest breakdown of where the two sites differ.

Mounjaro comes in 6 doses, and the price varies significantly between them. A pharmacy that is cheapest for 2.5mg may not be cheapest for 15mg. This is why filtering by dose is essential. WeightCompare lets you select your specific dose (2.5mg through 15mg) and instantly see every pharmacy’s price for that exact dose, sorted from cheapest to most expensive. You see the real price you will pay, not a range or a starting price. Monj splits its pricing across multiple separate pages: a retail price list, a discount price list, and individual pharmacy pages. There is no single table where you can select your dose and see all pharmacies ranked side by side. You end up opening multiple pages and scrolling through long lists to piece together which pharmacy is actually cheapest for your dose. When you are comparing 70+ pharmacies across 6 doses, this difference in usability adds up quickly.

This is where things get serious, because an inaccurate price comparison site is worse than no comparison site at all. If you choose a pharmacy based on a wrong price, you waste time and may end up paying more than expected. WeightCompare checks pharmacy websites daily. When we find a price that does not match, we update our database within 24 hours. We also show whether each price includes the consultation, delivery, and needles, so the price you see is the price you pay. Users can report incorrect prices directly from any pharmacy page. Monj states that it tracks prices daily, but in practice, prices on the site can be weeks or months out of date. Their data often relies on publicly listed pricing, which many pharmacies do not update consistently on their own websites. During our full price verification sweep of 74 pharmacies in March 2026, we found multiple pharmacies where Monj’s listed prices did not match the actual website price. For patients comparing prices to save money, even a £5–10 difference per month adds up to £60–120 per year.

Both sites list GPhC-registered pharmacies, but coverage differs. WeightCompare tracks 74 pharmacies with dose-level pricing for each one. Every pharmacy has its own page showing all 6 doses, what is included in the price, Trustpilot rating, GPhC registration link, and a direct link to the pharmacy website. Monj lists a similar number of pharmacies, but splits them across retail and discount lists. Some pharmacies appear on one list but not the other, making it hard to get a complete picture. The discount list shows promotional and first-order prices, which is helpful, but mixing discounted and standard prices in separate tables can be misleading if you are not a first-time customer.

The listed price of Mounjaro is not always the full cost. Some pharmacies include the consultation, delivery, and needles in their price. Others charge these separately, meaning the headline price is lower but the total cost is higher. WeightCompare shows three clear tags on every listing: Consult, Delivery, and Needles. You can see at a glance exactly what is included. This is critical for making a fair comparison. Monj does not consistently show what is included in each price. Some pharmacy listings mention delivery or consultation details, others do not. This makes it difficult to do a true like-for-like comparison, and you may think a pharmacy is cheaper when it actually has hidden costs on top.

Finding the right pharmacy should take seconds, not minutes. WeightCompare is built as a single-page comparison tool. Select your dose, see every pharmacy ranked by price, click through to a pharmacy page for full details, or visit the pharmacy directly. No account needed, no popups, no ads. Monj spreads its information across many separate pages and blog-style posts. The retail price list, discount price list, price comparison page, individual pharmacy pages, and cost calculator are all on different URLs. Navigation requires multiple clicks and page loads to find what you need. The site also uses a WordPress blog layout, which means pricing data is mixed in with editorial content, making it harder to quickly scan and compare.

Both sites earn revenue through affiliate links, which is standard for comparison sites. The important question is whether affiliate relationships influence rankings. WeightCompare ranks pharmacies by price alone. Affiliate and non-affiliate pharmacies appear in the same list, sorted by price. We clearly mark affiliate links with the sponsored rel attribute. Non-affiliate pharmacies still get a direct link to their website. Monj also states that it does not accept payment for placement. However, the site accepts referral codes and referral links from users, and promotes discount codes for specific pharmacies, which can create the appearance of favouring certain providers over others. Monj also separates pharmacies into discount and retail lists, which means pharmacies with affiliate discount codes get their own dedicated page with more prominent placement.

If you want to quickly find the cheapest Mounjaro for your specific dose with confidence that the price is accurate and up to date, WeightCompare is the more reliable tool. The single-page dose filter, transparent inclusion tags, and daily price verification mean you can make a decision in under a minute. Monj has built a community around Mounjaro pricing and offers useful editorial content, but as a price comparison tool, the split-page layout, inconsistent price accuracy, and lack of dose-level filtering make it harder to use for its primary purpose: finding the cheapest pharmacy for your dose. Ultimately, we would encourage you to check both sites and verify the final price on the pharmacy’s own website before ordering. But if you only have time to check one, we believe the data on WeightCompare is more accurate and easier to act on.