Dropping an A level in first year? Doing a third year and applying to med uni?

Yes, taking your A-levels over 3 years in that manner is likely to be an issue for quite a number of medical schools. The ideal situation would have been to swap maths for something else much earlier in year 12.
Applying at 19 would be the same as applying at 18, you're still a school leaver. None of the admissions requirements change and you aren't a "postgraduate" - that's for people who already have a degree. If you did hypothetically go through with this process you'd need to apply in your "year 14", and list your achieved grades for biology and chemistry and your pending grade for the new A-level. You'd otherwise take the UCAT at the same time as if the year 14 was actually year 13.
However there is a big difference between completing 3 A-levels over 2 years and applying after a gap year for example, and applying after completing 3 A-levels over 3 years - as medical schools normally want to see applicants have done a "full academic load" of A-levels in the normal amount of time. You may be unable to make a competitive application for many medical schools.
You'd probably need to look at medical schools and see which ones won't consider the fact you're doing A-levels over 3 years (if any). Otherwise you may need to look into continuing with maths and working with your school to get a lot of help to try and bring that up, although if you're predicted a U after year 12 it may be too late to reasonably catch up as that probably indicates most of the foundational material from year 12 you aren't able to utilise going into year 13.
Unfortunately it's a bit of a pickle. There is graduate entry medicine as a longer term option but that's generally not the best thing to aim for as a school leaver, but I'm not too sure what you can do to ameliorate taking A-levels over 3 years if you go that route otherwise. @GANFYD may know if any medical schools don't have an issue with that (with or without extenuating circumstances)?

I am currently in year 12 (first year of college) and im taking A level Biology, A level Chemistry and A level Maths. I am yet to sit my end of year exams to get my predicted grades but on the last tests I got an A in biology, B in chemistry and a U in maths🥲 Now as you can tell Biology and Chemistry are going pretty good compared to maths. I had the opportunity to drop out if maths in the beginning of the school year but i decided that as we go through it might get better, but it didn’t it’s only been getting worse, keeping in mind I've never had such low grades before in my life.
So i have been thinking about it a lot and i thought that maybe i could drop a level maths end of this year and pick a new a level - psychology to start in year 13 and therefore do a third year so i can finish all my a levels.
I want to apply to a uni with medicine but i was concerned if they will look at me differently having done a third year and if that would affect my application in any way? I am also confused on the times for sitting the UCAT and the actual application process when i would be doing an extra year? Would i just keep the two grades from my Biology and Chemistry a level and then sit my ucat at the beginning of my third year? And also i would have to apply beginning of third year as well? Or does anything change?
Also wondering if the requirements for a levels and gcse for applying to uni change if you are doing a third year and get into uni when ur 19 instead of 18? As obviously there are changes to requirements between postgraduate and undergraduate entry but I wasn’t sure if that has anything to do with me?
Overall im extremely confused about all of this and I don’t know who to speak to about it all so any help would be appreciated!

hey,
in terms of taking an extra year that's probably a preference between specific med schools which you'd have to probably look at or consult them directly about. i remember when i applied there were a number of schools who said they wouldn't accept applicants who had re-sat year 12 without extraordinary circumstances. however they might not interpret your situation in the same way.
about the ucat, you have to sit the exam within the cycle immediately before you apply. for example, if you were applying october 2024, you'd have to sit your ucat during the summer 2024 cycle if that makes sense. i dont think taking an extra year would affect it, as i remember the ucat results were only valid for an application made immediately after you sat the exam.
i took 4 a level initially (maths, chemistry, bio and psych) as my school made us and i planned to drop psychology but ended up dropping maths at the end of year 12 because i just found it so boring. i've really enjoyed psychology instead so i would definitely recommend it as a subject! i also found that many of my interviewers for med school found psychology an interesting subject as it's very client-focused with lots of ethics and similar to medicine in that aspect
hope this was helpful and good luck!

i have emailed some unis asking them about this as I can’t seem to find any information regarding this on their website so we will see what they say

You would be better off re-starting Yr12 doing chem, bio and whatever 3rd A level you decide upon. This would mean you were counted as a resit student, but there are plenty of med schools that will accept A levels done over 3 yrs, provided you sit all 3 together. Some may ask for an A* in a subject to reflect the fact you have studied it for 3 years rather than 2. There are very few, if any, med schools who will accept 2 A levels in one sitting and an extra one sat a year later

Thank you I really think that if i decide to go down that route i will absolutely love psychology! I have emailed some unis. Imperial have replied to day that they won’t accept me if i do a third year soo we will see what the others say

PRSOM!