When Should I Take Thyroid Medications

When Should I Take Thyroid Medication?
I get this question asked a lot because of the difficulty often-times of taking Synthroid,
Levothyroxine or Armour first thing in the morning and then having to wait 4-!" minutes before
consuming anything else, even other #rescri#tions or su##lements$ I decided to do a good bit of
research to identify the underlying reason why medical doctors, #articularly our
endocrinologists, recommend taking the medications in the morning$
%he main reason a##ears to avoid trouble falling aslee#, as for some #eo#le thyroid medication
can cause trouble with slee#$ %his is likely because of the relationshi# between the adrenal
hormone cortisol and the &y#othalamus-'ituitary Axis which regulates all hormones in the body,
including %S&$
(echanically, levothyroxine and Synthroid works no differently in the #resence of food as in its
absence$ )hat changes is how much of the drug is absorbed with some #ublished studies
showing about a *"+ dro# if Synthroid is taken with food, com#ared to an em#ty stomach$
,f interest is that two im#ortant studies #ublished in medical -ournals have found that taking the
same dose of thyroid medication at bedtime may actually be better than taking it first thing in the
morning$ A *"". study #ublished in the -ournal /linical 0ndocrinology, and a follow-u# larger
randomi1ed trial re#orted in the 2ecember *"3" issue of the Archives of Internal (edicine both
showed this res#onse$
%he studies were #rom#ted by observation that some #atients had im#roved thyroid hormone
#rofiles after they switched from taking their levothyroxine in the morning to bedtime$ 4ot only
did they evaluate the im#act of thyroid hormone levels by changing the time of medication, they
also evaluated the im#act this had on %S& and thyroid hormones and thyroid hormone
metabolism$ %he studies were fairly conclusive in their findings, which the researchers said were
5striking6 and which have 5im#ortant consequences for the millions of #atients who take
levothyroxine daily$6
7esearchers re#orted that taking medication at bedtime, rather than the morning, results in
5higher thyroid hormone concentrations and lower %S& concentrations$6 %S& decreased and
8ree %4 levels rose in all #atients by changing %4 ingestion from early morning to bedtime and
%9 levels rose in all but one sub-ect$ And %S& decreased irres#ective of the starting %S&
levels, suggesting better absor#tion of the thyroid medication when taken in the evening$
Interestingly, the researchers found that the circadian %S& rhythm -- the ty#ical daily
fluctuations of %S& that occur during a *4-hour #eriod : actually did not vary$
%he researchers suggested several ex#lanations for the im#roved results;
• 0ven when waiting at least 9" minutes to eat, breakfast may be interfering with the intestinal
absor#tion of levothyroxine$
Akiba Green, DC, BCIM • 19607 West Catawba Avenue • Cornelius, NC 20!1
"70#$ 97%!99! o&&i'e • "70#$ 97%!991 &a(
• <owel motility is slower at night, which means that it takes longer for the levothyroxine tablet
to transit through the intestinal system, resulting in longer ex#osure to the intestinal wall,
and therefore, better u#take of the medication$
• %he conversion #rocess of %4 to %9 may be more effective in the evening$
%he researchers found that the #atients taking nighttime levothyroxine had a dro# in %S& of
3$* -- which is a significant change$ %he free thyroxine =8ree %4> level went u# by "$". ng?dL,
and total triiodothyronine =%otal %9> went u# by @$ ng?dL$ According to the researchers, there
were no significant changes in the other factors$ %he researchers in both studies concluded
that, given the im#rovement in thyroid hormone levels, #hysicians should consider #rescribing
levothyroxine to be taken at bedtime$
)ith this research #ublished, I feel the following ma-or im#lications exist for many of our
#atients$
• 8irst, itAs easier, as you donAt have to worry about when to eat breakfast$
• Second, itAs easier to take your su##lements, foods and medication including calcium
and iron that can interfere with thyroid medication absor#tion$
• 8or those with blood sugar #roblems, es#ecially my #atients with reactive hy#oglycemia
=low blood sugar>, this would make it tremendously easier in the morning to get your day
started$
• 8ourth, it might offer some im#rovement in sym#toms to #eo#le who are -ust not getting
o#timal absor#tion by taking thyroid medication during the day$
)hile these only re#resent a few studies, they confirm what many #atients have been re#orting
for years -- that they feel better if they take their thyroid medication in the evening, rather than
the morning$
I do not advocate you switch on your own, but would absolutely recommend you tell
your health care practitioner who prescribed your thyroid hormone that you want to try
changing the time you take your prescription to bedtime, versus morning. And i you
decide to change to taking your thyroid medication in the evening, make sure we check
your thyroid levels via blood test in si! to eight weeks to help us to determine i you need
to ad"ust the dosage or timing o your medication.
I do need to caution those of you on Armour, 4ature%hroid or other %9 based thyroid-hormone
re#lacement medications$ %his research was not done on %9 but only %4 and so we sim#ly
donAt know if the results will be the same$ I am not o##osed to you trying the same thing we are
advocating, but kee# in mind slee# quality could be im#acted in some #atients$
Akiba Green, DC, BCIM • 19607 West Catawba Avenue • Cornelius, NC 20!1
"70#$ 97%!99! o&&i'e • "70#$ 97%!991 &a(