students don't automatically get free prescriptions but can get an exemption certificate by completing form HC1 every year.
the form is an enormous faff to complete and tbh if you are generally healthy it's not worth it - if you typically only need prescriptions maybe twice a year you are effectively working for less than minimum wage going through all the admin for the sake of saving £18.
however if you need prescriptions regularly and don't have a well-paid holiday/weekend/ evening job making you look wealthy, then it it's definitely worth it.
Students
If you're a student, you need to include evidence of all grants, bursaries and awards you receive. Normally this will consist of an award notice showing how much money you get.
If you applied for a student loan, we need to see a copy of the financial assessment that was carried out, regardless of whether a loan was actually awarded.
The full amount of student loan available to you will be included as income in your assessment. This includes the income-assessed and the non-income assessed loan elements, regardless of whether an application was made for both elements, and any assessed contributions to the loan regardless of whether they are actually paid.
from low income scheme website. Unlike student loans, parental income is not taken into account.