What medication is safe, Janumet or metformin?

In general, if diet and exercise alone are not good enough, the first drug they try for type 2 diabetes is metformin because it is safe and it is the drug that physicians have the most experience with. Metformin has been considered the diabetes drug least likely to cause hypoglycemia (low blood sugar). Going into a coma because of low blood sugar is a big deal, especially if you live alone like I do.)

Just reading up on Januvia (sitagliptin), it sounds similarly safe to me.

The best thing to do is ask your own physician or pharmacist what is safest for you. Is just metformin enough, or do you need both?

What is Janumet?
Janumet contains a combination of metformin and sitagliptin. Metformin and sitagliptin are oral diabetes medicines that help control blood sugar levels.

Metformin works by decreasing glucose (sugar) production in the liver and decreasing absorption of glucose by the intestines. Sitagliptin works by regulating the levels of insulin your body produces after eating.

Janumet is used together with diet and exercise to improve blood sugar control in adults with type 2 diabetes mellitus.

Janumet is not used to treat type 1 diabetes.

Source: https://www.drugs.com/janumet.html

Metformin is an oral diabetes medicine that helps control blood sugar levels.

Metformin is used together with diet and exercise to improve blood sugar control in adults with type 2 diabetes mellitus.

Metformin is sometimes used together with insulin or other medications, but it is not for treating type 1 diabetes.

Metformin is also used off-label to treat polycystic ovary syndrome (PCOS).

Source: https://www.drugs.com/metformin.html

Click on the link: https://www.drugs.com/compare/janumet-vs-metformin

Regarding safety, it varies from person to person as everyone reacts differently to medications. I would have to say if taken as prescribed by your DR. you should not have a problem with either one according to how your organism responds to the medication. There are always possible side effects, you may experience a few of the common ones which subside in a week to 10 days, and are quite common or you may not experience any of the potential side effects.