Can you take Melatonin 1 mg long-term?

I am at retirement age, healthy, I do not take medication, I have been using melatonin 1 mg in a very low dose for 2 years and I feel great, it gently affects my falling asleep. I read about the pros of using it, but also about the cons that there are no long-term studies. and use for up to 6 weeks. However, I can see from myself that b low dose is well tolerated. Is there any more knowledge on the subject that longer use... I don't think I'm an exception... It does not cause any side effects.