John Answers Your Questions

How long do I need to wait after taking thyroid medication, (eg. Synthroid), in the morning before taking other supplements...or coffee, or eating?

[Note: Official answer: Follow your Dr.'s recommendation.]

Unofficial discussion:

After decades of inquiry and experimentation, I have found that it is optimal to leave at least 40 minutes between empty-stomach supplements and food.

Yet, since thyroid medications such as Synthroid take 2-3 hours to reach peak blood levels, this is often how long people are instructed to wait before taking or eating anything else. But this can be hard to fit in and according to most sources is unnecessary.

Recommendations from numerous sources say an hour is adequate. This is before taking other supplements or eating. (One source I found even said taking it with breakfast may be fine.(?) Not so sure about that.) So this means for people who want to take their thyroid meds first thing in the morning, you can put them out with a glass of water, and when you get up to empty your bladder swallow it then.

You can wait an hour or more, and then take your empty-stomach supplements, and wait a minimum of 30 minutes, (40 or more is better), before eating.

Most people can manage the 90 minutes...some can't. For these, taking your thyroid medication at night is also an option, and is said to produce marginally better absorption. (See first source)

Caffeine will affect absorption of levothyroxine, so leave a minimum of an hour between, but this can be avoided by using liquid or gel cap formulation. See the quotes and sources below:


“To completely avoid an issue with food interaction, 45 to 60 minutes should elapse between the levothyroxine dose and breakfast,” says Dr. Rosenfeld. “Most people, however, feel that 30 minutes is adequate. Increasing the time may be beneficial for those patients who do not appear to be absorbing the drug.
"Although dietary fiber and foods including milk (both dairy milk and calcium-fortified plant milks), soy, and coffee may delay or impair the absorption of levothyroxine, you can avoid this issue by waiting at least 30 to 60 minutes before eating or switching to the liquid or gel cap formulation of the drug, according to a systematic review published in Pharmaceuticals in March 2021.⁴" 

"Administer levothyroxine on an empty stomach (acidity increases absorption) at least 30 to 60 minutes before breakfast..."


Other Sources: -the review mentioned above - two to three hours to Tmax - American Thyroid Association

 Re: The 8 Forms Of Vitamin E: Are Tocotrienols Superior To Tocopherols? The New Roots vitamin E has soy as an ingredient. I just started taking vitamin E; I read that if taking a fish oil - I take OHV Neptune Krill Oil - it is important to also take a vitamin E. Are there any options without soy?

Yes! The new tocotrienols from E Annatto specifically state that it contains NO soy. i.e.:
"Does NOT contain dairy, starch, sugar, wheat, gluten, yeast, soy, corn, egg, fish, shellfish, salt, or tree nuts."
Yet, going further into your concerns: if your body was under a lot of oxidative stress, such as undergoing cancer treatments, then yes, fish oils could be problematic, as they too may oxidize.
Krill oil contains an antioxidant (astaxanthin) that will prevent this, and has many additional benefits. Still you would need to be under a lot of toxic stress for a Canadian-produced fish oil to become oxidized in your bloodstream.
One could also use E Annatto to prevent this, and it would be very suitable, because of the higher antioxidant potential of tocotrienols, and the additional carotenoids it naturally contains.
All of that said, I take Synergy-3 Optimized Omega (providing EPA, DHA, GLA) for the higher dosages of each essential fat, AND I take Krill oil for the highly penetrating delivery form of astaxanthin. 
I am also taking the EAnnatto instead of Vitamin E to see if my wellbeing increases. All three provide unique benefits, and compliment each other.

Re: "L-Carnitine vs Acetyl-L-Carnitine: What's the Difference?" What if I want brain functionality AND energy? Do I take both supplements?


Because the mitochondria uses the acylated version, for brain functionality and energy if you have to choose one, choose acetyl-L-carnitine, as it crosses the blood-brain barrier.

On the other hand if what you are looking to do is lose body fat, lower your cholesterol, and improve your insulin sensitivity and blood sugar, because L-carnitine tends to be more active in the peripheral tissues, I usually recommend the L-carnitine.

Of the two, after decades of using and recommending both, it is clear that people notice more distinct energy and alertness from the acetyl form.

I am curious - what kind of probiotics replenishes oral biome?

Though to some extent there will be a positive effect on the oral microbiome of any oral, edible, or chewable probiotic, the Blis-K12 trademark found in CulturedCare Probiotic Gum by Prairie Naturals contains a beneficial oral probiotic called Streptococcus salivarius, which is one of the first bacteria after birth to colonize the mouth and gut, where it exerts anti-inflammatory effects.

Approved claims from Health Canada include "Supports Ear, Nose & Throat Health, Helps Maintain Fresh Breath." I have to say for my breath, I've noticed a much bigger impact from our OHV Opti-Elite Probiotics, and also the "NOW Probiotic 10".

I would say, regardless of what you are trying to achieve with probiotics, never underestimate the effects of improving your gut microbiome on your whole body microbiota.



Sources: - anti-inflammatory effects of S.salivarius -translocation between mouth and gut -oral probiotics can be beneficial


I've read that you don't get as much of a bang for your buck if you don't use prebiotics along with probiotics. Is this the case?

Overall, yes a prebiotic can be very helpful, but I would say it's more important to find the right probiotic first.

Remember that people are going to vary in their response to prebiotics, just like they are probiotics. This is because of individual genetics, and the actual collection of different bacteria in their gut, which is so immense and diverse.

Hence, I would say the first step is to find a probiotic that produces a noticeable benefit for YOU.

The most common benefits noticed are that your stomach empties faster, less bloating, less gas, better digestion etc. Once you have found such a probiotic, many of which contain prebiotics like FOS, then start experimenting with other prebiotics.

Yes they can be very helpful for proliferating the probiotics. But remember this can just as easily include the soluble fibre in fruits and vegetables, or garlic, or onions, or a very long list of healthy foods, as it can be a specific prebiotic product.

Note: In our line we went with the strains that we had seen the most consistent results with over time, i.e. the DDS-1 acidophilus strain and the UABla-12 Bifidobacteria strains, with a response rate that I would estimate to be about 80%. (I have used the DDS-1 strain since the 1980's for food reactions, yeast and particularly allergies, and have been recommending these strains since 1993. Hence, I've had a long time to judge such a response rate.)


Hope This Helps! Be Well,


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