My mother is taking these arthritis pain relieving pills but wants to know if its dangerous to take?

The products is called Reumofan Plus, supposedly it comes from Tijuana Mexico.... ever since she started taking it she has felt much pain relief on her knee's and even recommended it to a friend of hers which had a hard time walking and after taking it she felt like she could run a marathon...these pills claim to be all natural. No side affects yet from taking them but she seems to be gaining a bit of weight ever since she took them, she works out every day.