I was 22 when I started university (with my then toddler DD in tow, and after having worked to pay my own way through) and I remember being absolutely horrified by the way in which my 18 year old peers behaved. But they were living away from home, and parental rules for the very first time, and... well... trying to figure out how to be independent adults. Now, those whom I stayed in touch with, are all responsible, hard-working individuals who are dreading the day upon which their own children go to university - and behave just like they did!
My DD's 19 now and is also in her first year of university. She also lives at home, as the university she wanted to go to is in our home-town. She and her peers are also struggling with the adjustment to not having teachers nag them about deadlines, about the expectations to be responsible for themselves/their own work, and - for her new friends - the fact that they're also expected to cook their own meals, do their own washing, pick up after themselves and, for a few, get jobs to fund their lifestyles. I have no clue how my DD is doing grade-wise. She's an adult. As long as I know she's doing her best, then I'm okay with that. Because it's her future she's working towards. Not mine. Hers.
My parents didn't know how I was doing at university all those years ago. Because I was an adult. Actually, because I couldn't attend my graduation (it clashed with a medical appointment for my DD - which was obviously more important than my donning a gown and a hat with a tassle on it!), I'm not even entirely certain that they know I even have a degree.
Obviously you don't want your DS to fail, and I do understand that completely. But biochemistry is hard. Even for someone without dyslexia. If your DS is getting 50pc in his labs - then he's doing okay. He only has to pass his first year. The grades don't matter until the 2nd year. Because of the huge adjustment that the students have to - in the majority - go through during their first year. Living away from home, especially in a different town, or city to your family, for the first time is hard. Combine that with lecturers who don't treat you as though you're a child, like your teachers at school/college did... and who expect you to be entirely responsible for your own work, alongside having to feed and clean up after yourself...? It's pretty rough. I'd be more upset, OP, if I were you, if I found out that he'd spent all of his money on booze rather than food, to be honest. Because believe me: that happens! Since the start of October, I've lost count of the amount of students we've had in our home for dinners, because they've spent all their money and can't afford to feed themselves (and also, I suspect, because they miss their own families and homes, and are desperate for just a slither of the comfort that even a relative stranger's homelife can provide them with).
Support your DS, be there for him, and cut him some slack. This is his life now, and you have to let him live it - as hard as that is.