Hello I am 23 yrs old I got my liver ultrasound done the size of my liver is 17.2cm which is mildly enlarged, but my lfts are normal ALT measuring 50?

Watch it. If there's no fatty change in your liver, just keep an eye on it. The ALT is probably higher than your friends, and it might be worth repeating off all meds that you can pass up, including "natural healing holistic herbal" stuff. I trust your physician has done labs as needed. Especially if you're a big guy, the liver span may be fine for you.