Brief Answer:
metformin one of better diabetes meds, statins reduce risk of hrt disease

Detailed Answer:
HI, thanks for using healthcare magic

It is true that these medications, like all medications or herbal supplements, have potential side effects.
Any medication or supplement that alters the level of any chemical in the body through any particular mechanism is associated with potential side effects.

These effects however are potential, they may not occur and in many persons , serious effects do not occur.

The vast majority of persons who use medications do not experience any serious effects.

Metformin- this is one of the best medications for diabetes

It will reduce your body's resistance to its own insulin, thereby help your body's insulin to work better. It will not cause weight gain and in some persons, actually cause weight loss.
It is is used not only in diabetics but also in prediabetics (persons heading towards diabetes) and in women with a condition called PCOS ( to reduce the insulin resistance ).

It can cause GI effects such as upset stomach, bloating or change in bowel habits but if this occurs your doctor can consider switching you to the slow release format that is less associated with these problems.

Statin- need to balance risk with benefits

Diabetes is associated with increased confirmed risk of heart disease and stroke. These are well known possible complications of diabetes.
Statins can reduce the risk of these occurring by helping to reduce the cholesterol.

Statins can cause muscle aches (no permanent damage and if occurs, resolves when discontinued) and pain in some persons and in may also be associated with an increase in the blood values of liver enzymes (though there may be no actual damage to the liver).

So there is the potential risk of effects occurring with the statins though ,as mentioned, the vast majority have no effects. If you do have effects then you can discontinue the medication after discussion with your doctor and consider an alternative.

Summary: all meds and supplements potential effects that may or may not occur.
There are risks associated with diabetes that will occur if not controlled.
It is understandable to be concerned about any potential effects but you should be ok.
If problems occur, then you can alter your medications.

I hope this helps, feel free to ask any other questions

---