Levothyroxine kicking in in the evenings

[trtthings]

Hi guys,

I've begun Levothyroxine treatment since last Friday, 50mcg a day, taken in the morning.

I'm finding that it functions in a way that I didn't expect. I take it in the morning and around 10h later I'm awake like I haven't been for years. This is the effect I was hoping to get from TRT. But why would it kick in so late?

As far as I can tell the half-life is 7 days which should provide relatively stable levels. I'd think the effect would be more even but it's kicking in around 5-6 PM. Until then I'm maybe slightly better but that's when I become 100% and that lasts until I fall asleep.

Any input? @Cataceous @Vince

All I can think of.. is something weird with the liver randomly converting a large batch of T4 to T3 late in the day. It doesn't make much sense.

 

[Vince]

Hi guys,

I've begun Levothyroxine treatment since last Friday, 50mcg a day, taken in the morning.

I'm finding that it functions in a way that I didn't expect. I take it in the morning and around 10h later I'm awake like I haven't been for years. This is the effect I was hoping to get from TRT. But why would it kick in so late?

As far as I can tell the half-life is 7 days which should provide relatively stable levels. I'd think the effect would be more even but it's kicking in around 5-6 PM. Until then I'm maybe slightly better but that's when I become 100% and that lasts until I fall asleep.

Any input? @Cataceous @Vince

All I can think of.. is something weird with the liver randomly converting a large batch of T4 to T3 late in the day. It doesn't make much sense.

I’m surprised at the results you’re getting. It will be interesting to see your labs. I usually wait 12 weeks, when I do a testosterone or thyroid protocol adjustment.

i’m happy it’s working so well for you, hopefully it will continue.

 

[HarryCat2]

Several thyroid docs have told me that some people do better taking their levo in the evening. They didn't offer an explanation.

 

[JA Battle]

As a first step I would make sure you are eating enough. Increasing thyroid hormones without enough fuel can increase stress hormone and catecholamine secretion.

 

[trtthings]

Free Triiodothyronine Has a Distinct Circadian Rhythm That Is Delayed but Parallels Thyrotropin Levels

Abstract. Context: TSH is known to have a circadian rhythm, but the relationship between this and any rhythm in T4 and T3 has not been clearly demonstrated.Obje

academic.oup.com

This is somewhat interesting but doesn't leave me with a single theory. Apparently FT3 seems to follow TSH in a delayed fashion.

 

[trtthings]

Been thinking this over back and forth.

I think the following theory makes sense:

@Cataceous @Vince

As we've seen in euthyroid subjects, the levels of T4 are relatively stable whereas TSH and T3 have a diurnal rhythm. FT3 following TSH by maybe 90 minutes, as if TSH is driving the T4 -> T3 conversion with little effect on T4.

There's a negative feedback with TSH, much like testosterone/estradiol and LH. So you supplement with Levothyroxine, it reaches the peak in the serum within 3 hours (although T4 levels are relatively stable). It's not unreasonable to think that this would cause some suppression and thus suppress the TSH mediated T4 -> T3 conversion for the next few (many) hours.

I feel the effects in the evening, so it's not unreasonable to think that by then I might have been getting some TSH and then T4 -> T3 conversion.

I've also read many stories by thyroid patients who were tired all day until they switched to an evening intake of T4. It seems counter-intuitive at first with the relatively stable levels of T4 (given the 1-week half life). But I'm still guessing it matters, at least for some.

I tried this myself now.. all the days I took 50mcg in the morning I started feeling it after around 10 hours. I tried one day with 75mcg in the morning and the onset was slightly later. Then I tried 75mcg in the evening and I started feeling the effect/being more awake/feeling better around noon the next day.

Doesn't really matter if I'm right or wrong as long as the end result is that I'm feeling better.

However I think this probably partially explains why some thyroid associations recommend/say patients often don't feel good until they have T4 levels high in the range or just outside of the normal range. I think the TSH suppression, firstly.. it suppresses the T3 secreted from the thyroid. If I recall this is thought to be about 20% of the total T3. And secondly it may be suppressing this T4 -> T3 conversion by suppressing TSH.

 

[Vince]

Been thinking this over back and forth.

I think the following theory makes sense:

@Cataceous @Vince

As we've seen in euthyroid subjects, the levels of T4 are relatively stable whereas TSH and T3 have a diurnal rhythm. FT3 following TSH by maybe 90 minutes, as if TSH is driving the T4 -> T3 conversion with little effect on T4.

There's a negative feedback with TSH, much like testosterone/estradiol and LH. So you supplement with Levothyroxine, it reaches the peak in the serum within 3 hours (although T4 levels are relatively stable). It's not unreasonable to think that this would cause some suppression and thus suppress the TSH mediated T4 -> T3 conversion for the next few (many) hours.

I feel the effects in the evening, so it's not unreasonable to think that by then I might have been getting some TSH and then T4 -> T3 conversion.

I've also read many stories by thyroid patients who were tired all day until they switched to an evening intake of T4. It seems counter-intuitive at first with the relatively stable levels of T4 (given the 1-week half life). But I'm still guessing it matters, at least for some.

I tried this myself now.. all the days I took 50mcg in the morning I started feeling it after around 10 hours. I tried one day with 75mcg in the morning and the onset was slightly later. Then I tried 75mcg in the evening and I started feeling the effect/being more awake/feeling better around noon the next day.

Doesn't really matter if I'm right or wrong as long as the end result is that I'm feeling better.

However I think this probably partially explains why some thyroid associations recommend/say patients often don't feel good until they have T4 levels high in the range or just outside of the normal range. I think the TSH suppression, firstly.. it suppresses the T3 secreted from the thyroid. If I recall this is thought to be about 20% of the total T3. And secondly it may be suppressing this T4 -> T3 conversion by suppressing TSH.

But of course that’s not the case for everyone. Some people have a hard time converting T4 into FT3, like me. So I seem to do better on the lower dose of T4 and supplement with T3 twice a day.

 

[trtthings]

But of course that’s not the case for everyone. Some people have a hard time converting T4 into FT3, like me. So I seem to do better on the lower dose of T4 and supplement with T3 twice a day.

I really think it's the same for me, i.e. I'd do better with T3 in the morning / afternoon.

 

[Fortunate]

Hi guys,

I've begun Levothyroxine treatment since last Friday, 50mcg a day, taken in the morning.

I'm finding that it functions in a way that I didn't expect. I take it in the morning and around 10h later I'm awake like I haven't been for years. This is the effect I was hoping to get from TRT. But why would it kick in so late?

As far as I can tell the half-life is 7 days which should provide relatively stable levels. I'd think the effect would be more even but it's kicking in around 5-6 PM. Until then I'm maybe slightly better but that's when I become 100% and that lasts until I fall asleep.

Any input? @Cataceous @Vince

All I can think of.. is something weird with the liver randomly converting a large batch of T4 to T3 late in the day. It doesn't make much sense.

I have noticed a very similar experience, but with sustained release T3. As instructed, I take it first thing when I get up in the morning. I generally don't feel much of anything until late afternoon, early evening, when I feel tons of energy. I assumed it was because it is a sustained release formulation, but don't really know.

It would really be more useful to me if I had those energy levels earlier in the day. I suppose I could take it at night, but that is not how I was advised. Another option is to try a standard formulation that is not sustained release? Anyone notice similar experiences? Any thoughts on sustained release vs. standard vs. altering taking meds at different time of day?

 

[Match]

I always fast and wait a little without food, for better absorption. NUnca i noticed these symptoms that speak

 

[Fortunate]

Looking back, I may have been tracking two different things. Around the time I was on T3, I had also started a new testosterone cream protocol. I went off T3 a while back. Once I get on a consistent testosterone protocol, I would consider trying T3 again, but only if symptoms warrant it.