also, as my girlfriend is having some source unknown knee pain (like it suddenly hurts and kinda makes some popping sound), so i'm thinking about giving her some glucosamine sulfate. I've read a bit about it on the internet and is in fact unsure if it's safe or not. Can someone explain about glucose sulfate? and How can i determine what her problem is?

I can't really speak to the oil part of your question but do want to give you a little info on knees.

There are a lot of things that could be going on with her knees. It could be joint related or it could be a tendon. The only way to really know is to see a doctor and have X-rays done. You don't want to just try treating something without knowing what is going on.

That being said, I have JRA and my knees are problematic. I've had steroid shots in both and that's helped. Maintenance wise I do take glucosamine and it helps with pain and mobility. It's not an overnight thing, takes a couple of weeks in your system for you to see results. This will help if it's a joint problem. If it's a type of tendon problem then it won't. I have a friend that has a very small knee cap and it slides. What she has to do is exercise and build up the muscles around it to help hold it in place. That could be your girlfriends problem too.

It's impossible to know what would work best unless you really know what's going on with it.

Really, best bet - get into a doctor and move forward from there.

I'm still confused though, does glucosamine have any side effects?

Anything you put into your body has an effect.

http://altmedicine.about.com/cs/arthritis/a/Glucosamine.htm

I have never had any of the listed side effects and I've taken it nearly daily for the last three years. They did say that most are made from shell fish, so if you have an allergy to that, it could be very serious; like DEATH serious. It's always common sense to investigate a med or supplement before you start popping them. I commend you for doing that!

In terms of the Omega Oils, as I said, I'm not a good person to ask.