Looking for something else entirely - related to England, not Wales - I happened to see this:
Wales moves to longer standard prescribing cycles to 'free capacity'
Pharmacy Magazine, 14 Feb 2022
From April this year, GPs in Wales are being asked to move to a 56-day prescribing cycle for suitable patients to help “release capacity” for practices and community pharmacies.
In a guidance document published last Tuesday (February 8), Community Pharmacy Wales and the Welsh General Practice Committee recommended that the standard prescription cycle be increased from 28 days to 56 to allow GPs and pharmacies to focus more on services, and to reduce the number of trips patients have to make to their pharmacy or doctor.
This follows a Government report last year looking at dispensing volumes in pharmacies that found Wales was “behind other countries” in moving to extended prescribing intervals, and that there was only “limited” evidence to uphold the claim that 28-day prescribing helps reduce medicine waste.
pharmacymagazine.co.uk/news...
I suggest this updated policy would usually apply to thyroid hormone medicines - once on a stable dose.