Why Is Merilog So Hard to Find? [Explained for 2026]

Why Is Merilog So Hard to Find?

If you've been prescribed Merilog (insulin aspart-szjj) and your pharmacy keeps telling you it's out of stock, you're not alone. Since its launch in mid-2025, many patients have struggled to fill their Merilog prescriptions — and the reasons go beyond simple supply and demand.

In this guide, we'll break down exactly why Merilog is hard to find, what's happening in the insulin market, and what steps you can take right now to get your medication.

What Is Merilog?

Merilog is a rapid-acting insulin biosimilar made by Sanofi. It was FDA-approved on February 14, 2025, making it the first-ever biosimilar to NovoLog (insulin aspart). Like NovoLog, Merilog is injected 5 to 10 minutes before meals to help control blood sugar in adults and children with type 1 or type 2 diabetes.

It comes in two forms: a 10 mL multiple-dose vial and a 3 mL SoloStar prefilled pen, both at 100 units/mL. Because it's a biosimilar — not a generic — it went through rigorous FDA testing to prove it works the same as NovoLog.

Why Is Merilog Hard to Find Right Now?

1. It's Still a New Product

Merilog only became available in pharmacies in July 2025. That means it's been on the market for less than a year. Many pharmacies haven't fully stocked it yet, and some wholesalers are still building up their distribution networks. When a new medication launches — especially an insulin biosimilar — it takes time for the supply chain to catch up to patient demand.

2. Insurance Formulary Transitions Are Ongoing

When a new drug launches, insurance companies and pharmacy benefit managers (PBMs) need to decide whether to add it to their formularies. This process can take months. Some plans have added Merilog, while others are still evaluating it. If your insurer hasn't approved Merilog yet, your pharmacy may not carry it because there's limited demand from their customer base.

3. The Insulin Market Is in Flux

The broader insulin aspart market has been experiencing disruptions. Novo Nordisk discontinued its unbranded insulin aspart (an authorized generic of NovoLog) effective December 31, 2025. At the same time, Fiasp (another insulin aspart product) has been dealing with ongoing FlexTouch pen shortages expected to last into early 2026. These disruptions have pushed more patients toward alternatives like Merilog — but supply hasn't kept pace.

4. Pharmacy Stocking Decisions

Pharmacies, especially large chains, tend to stock the insulin brands that most of their patients use. Since Merilog is new, many pharmacies haven't added it to their regular inventory. Independent pharmacies may be more willing to special-order it, but chain pharmacies often follow corporate formulary guidelines.

What You Can Do Right Now

Use Medfinder to check availability. Medfinder helps you search for pharmacies that have Merilog in stock near you — in real time. Instead of calling pharmacy after pharmacy, you can check availability from your phone.

Ask your pharmacy to order it. Even if your pharmacy doesn't stock Merilog, most can order it from their wholesaler within 1 to 2 business days. Ask the pharmacist to place a special order.

Try independent pharmacies. Independent and compounding pharmacies are often more flexible about ordering medications that aren't in their regular inventory. They may also have connections to different wholesalers.

Talk to your doctor about alternatives. If you can't find Merilog, other rapid-acting insulins may be available. NovoLog, Humalog, Admelog, and Apidra are all in the same drug class and may work for you while Merilog supply stabilizes.

Check Sanofi's savings programs. Sanofi offers Merilog for $35 or less per 30-day supply through its Insulins Valyou Savings Program — regardless of insurance status. If cost is a concern along with availability, this program can help. Learn more about saving money on Merilog.

Will Merilog Become Easier to Find?

Yes — the outlook is positive. As Sanofi scales production and more insurance plans add Merilog to their formularies, availability should improve throughout 2026. The discontinuation of Novo Nordisk's unbranded insulin aspart actually creates more market opportunity for Merilog, which should incentivize broader distribution.

In the meantime, being proactive is key. Use tools like Medfinder, stay in touch with your pharmacy, and keep your prescriber informed if you're having trouble filling your prescription.

Final Thoughts

Merilog represents an important step forward for insulin access in the U.S. — it's the first rapid-acting insulin biosimilar, and Sanofi's $35 pricing commitment makes it one of the most affordable options available. The availability challenges are real but temporary. With the right tools and a little persistence, you can find Merilog and keep your diabetes management on track.

Need help finding Merilog in stock? Try Medfinder — it's free and takes just seconds to search.