{"product_id":"thyroid-function","title":"Thyroid Function","description":"\u003cp\u003eTSH with both free hormones — not TSH on its own.\u003c\/p\u003e\u003ch3\u003eMarkers measured (3)\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eTSH\u003c\/li\u003e\n\u003cli\u003eFree T3\u003c\/li\u003e\n\u003cli\u003eFree T4\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eTiming\u003c\/h3\u003e\u003cp\u003eTake in the \u003cstrong\u003emorning, ideally fasted\u003c\/strong\u003e. TSH is at its highest overnight and drifts down through the day, and it reads a little higher fasted than after food. Fixing the time is what makes this test comparable with the next one.\u003c\/p\u003e\u003cp\u003eIf you take levothyroxine, take the sample before that day’s dose. A dose taken a few hours earlier lifts free T4.\u003c\/p\u003e\u003cp\u003eIdeal, not required. Glucose is the only marker we sell that is invalid unfasted. If fasting does not fit your day, take it anyway and do the same next time.\u003c\/p\u003e\u003ch3\u003eVenous or finger prick\u003c\/h3\u003e\u003cp\u003eSame markers either way.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eVenous\u003c\/strong\u003e — a professional takes the sample. You choose one of the four blood draw options in your basket, before checkout. Book Monday to Thursday and post the same day.\u003cbr\u003e\u003cstrong\u003eFinger prick\u003c\/strong\u003e — an at-home test you do yourself, in under ten minutes. No blood draw appointment needed. Post it the same day it is taken. The timing above still applies. Collect Monday to Thursday and post the same day. Finger-prick samples fail more often than venous ones; \u003ca href=\"\/pages\/capillary-testing\"\u003ewhat that means\u003c\/a\u003e.\u003c\/p\u003e\u003ch3\u003eBefore you order\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003ca href=\"\/pages\/how-it-works\"\u003eHow it works\u003c\/a\u003e — the four blood draw options, what each costs, and the process end to end.\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"\/pages\/choosing-a-test\"\u003eChoosing a test\u003c\/a\u003e — what to check before buying any blood test, here or anywhere.\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"\/pages\/biomarker-guide\"\u003eBiomarker Guide\u003c\/a\u003e — every marker we run, in plain English.\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"\/pages\/body-guide\"\u003eBody Guide\u003c\/a\u003e — what each organ and system actually does.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eTurnaround:\u003c\/strong\u003e the lab reports this test within 24 hours of receiving your sample, counted in working days. Most samples reach them within about 3 days of posting. Full detail on our \u003ca href=\"\/pages\/turnaround-times\"\u003eTurnaround Times\u003c\/a\u003e page.\u003c\/p\u003e\u003cp\u003e\u003cem\u003eWe do not interpret results. Not medical advice or a diagnosis.\u003c\/em\u003e\u003c\/p\u003e","brand":"N1 Health","offers":[{"title":"Finger prick","offer_id":58266849542488,"sku":"N1-P-THYROID-FUNCTION-C","price":45.0,"currency_code":"GBP","in_stock":true},{"title":"Venous","offer_id":58266849509720,"sku":"N1-P-THYROID-FUNCTION-V","price":45.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1007\/1533\/1928\/files\/thyroid-function-v5.png?v=1787608803","url":"https:\/\/n1health.co.uk\/products\/thyroid-function","provider":"N1 Health","version":"1.0","type":"link"}