Just a quickie...

[janey1234]

For the past 2 years I have been using Medichecks fingerprick home testing to monitor my thyroid levels. Each time I have posted my results here and sought your invaluable advice and then my GP has been happy to accept the results and the advice given.

However, it came to my attention last time that I may have been leaving too large a gap between stopping my Levo' and testing. I take my Levo ' at bedtime so if tested on a Monday morning the last Levo' would have been taken on Saturday night.

I have been taking 125 Levo for quite a while now and, touch wood, I haven't felt this good for a long time. I think I've found my right level of Levo at last. I did try 150, following my last results post, but I didn't feel comfortable, heart seemed to be beating faster so after 2 weeks I dropped back to 125 and I felt great.

My questions are...

1. Should I leave off the Saturday night Levo' & take it Sunday morning instead, which would then mean 24hrs before the Monday morning test, instead of 36hrs?

2. Will my thyroid results really look that different? I read about 'half lives' but didn't really understand it.

Thank you ☺

[SeasideSusie Remembering]

Janey

It depends on which result is more important - TSH or FT4.

If you leave more than 24 hours between last dose of Levo and blood draw you will have a false low FT4. It won't make much difference to TSH. Time of day of blood draw affects TSH. TSH is highest very early morning and lowers through the day, eating can also affect TSH and drinking coffee does too.

[janey1234 in reply to SeasideSusie]

Thank you. My TSH is always suppressed, FT4 good, FT3 ok (ish) so from what you've said my results shouldn't look that different (maybe just a slightly higher FT4, which should still be in range) at least from the point of keeping my GP 'satisfied'.

Thanks again ☺

[Chromegirl32 in reply to SeasideSusie]

Does tea make the same difference as coffee?

[SeasideSusie Remembering in reply to Chromegirl32]

Chromegirl32

I don't know, I've only read that coffee affects TSH. But, always advised here when having a thyroid blood test is delay breakfast and have water only until after the blood draw. Makes no sense to do anything that will give a false result.

[greygoose]

If you've always done it this way, and you feel good, I wouldn't change anything. It's only if you start to feel bad that it might be advantageous to leave just 24 hours to get a true FT4 reading - if your doctor even looks at it.

[janey1234 in reply to greygoose]

I think I will probably do it the same way as before then ...just needed to check I wasn't drastically altering my results. Thanks @greygoose 🙂

[greygoose in reply to janey1234]

You're welcome.

[Fifteen in reply to greygoose]

Have just finished taking blood for a Blue Horizon check and saw these messages. Hopefully my results will be accurate - I have not taken Levo or Liothyronine since Saturday, so 3 days.

[greygoose in reply to Fifteen]

Then they won't be accurate. 3 days is too long. The recommended time gap is 24 hours for levo, and 8 - 12 hours for T3. You will have very false lows.

[Fifteen in reply to greygoose]

Thank you. I will do them again next week.

[greygoose in reply to Fifteen]

You're welcome.