Can I Have Caffeine If I Have Hashimoto’s Disease?

If you have been diagnosed with Hashimoto's disease, you may have a lot of questions. One question that sometimes comes up is whether it is a good idea to consume caffeine if you have Hashimoto's and are on medication.

Have you considered clinical trials for Hashimoto's disease?

We make it easy for you to participate in a clinical trial for Hashimoto's disease, and get access to the latest treatments not yet widely available - and be a part of finding a cure.

What is caffeine and how does it work?

Caffeine is a popular stimulant found in coffee, tea, kola nuts (used to flavor soft drinks), and cacao (chocolate).

Synthetic caffeine is also found in energy drinks, many cold medicines, and similar. It is used to counteract the drowsy effect of some medications, increase alertness, and help you feel better when you have a cold.

Many people think that a cup of coffee or tea first thing in the morning helps them wake up and start the day. Culturally, caffeine is so acceptable that people often forget that it is, in fact, a drug, albeit a very safe one.

There is a range of effects that caffeine can have on the body, which include:


Caffeine stimulates your central nervous system, increasing alertness and energy. Some people feel that caffeine can help them lose weight, but, on its own, any effect is minimal.


Caffeine acts as a diuretic, causing you to urinate more. This can help you get rid of excess water and salt.

Acid production

The consumption of caffeine leads to an increase in stomach acid, which sometimes results in heartburn.

Blood pressure

Caffeine use increases blood pressure, which is the reason many doctors recommend that people with hypotension avoid caffeine.

Prevention of calcium absorption

Caffeine potentially interferes with calcium absorption. You should avoid drinking a caffeinated beverage too close to taking a calcium supplement to ensure that your body absorbs the entire dose.

Up to 400mg of caffeine, a day is not harmful, although using too much can result in conditions such as insomnia and headaches.

An eight-ounce cup of brewed coffee contains around 70-140mg of caffeine, while the same quantity of black tea contains around 20-30mg.

Caffeine can be physically addictive and cause mild withdrawal symptoms if you abruptly stop consuming it. Some people are more sensitive to caffeine than others, and extremely sensitive people may avoid caffeine because they don't like how it makes them feel.

What is Hashimoto's disease?

Hashimoto's disease or Hashimoto's thyroiditis is a progressive autoimmune condition that affects your thyroid. It leads to an underactive thyroid that causes symptoms such as fatigue and weight gain.

While not curable, it is easy to manage with thyroid replacement medication. It primarily affects middle-aged women, although it can occur to those of any age or gender. The symptoms are the same as for other forms of hypothyroidism.

Hashimoto's can only be diagnosed by a blood test that shows that you have antibodies that can affect your thyroid.

How does caffeine affect you if you have Hashimoto's?

Some people with undiagnosed Hashimoto's may use more caffeine to try and deal with fatigue and drowsiness. Too much caffeine can cause issues such as not sleeping.

Some things that you should consider:

  • Caffeine speeds up your metabolism¹. This can cause temporary relief of hypothyroid symptoms, but can also potentially put more stress on your thyroid.

  • If you have hyperthyroid, then caffeine can make your symptoms worse.

  • There is some evidence that caffeine can, in fact, help moderate your immune system² and thus might help with any autoimmune disease, including Hashimoto's. The jury is still out, but, at least, there is enough evidence that consuming caffeine will not make Hashimoto's worse.

In other words, Hashimoto's is not made worse by caffeine, and in some cases, it might ease symptoms.

However, if you have untreated Hashimoto's, you should avoid self-medicating with large amounts of caffeine as it can increase the stress on your thyroid as well as potentially cause symptoms of a caffeine overdose.

There is, however, another relevant concern, and that is the interaction between caffeine and thyroid medication.

How caffeine interacts with thyroid medication

Caffeine can interfere³ with the absorption of your thyroid medication, resulting in your dosage being thrown off.

A study³ explored potential issues with coffee being used to wash down levothyroxine pills.

This is not a good idea. Caffeine causes the medication to pass through your gut faster, resulting in lower absorption. This effect is variable, so it is likely to result in your dosage becoming unstable and you getting hyperthyroid or hypothyroid symptoms, possibly both in a relatively short period.

However, it was also observed that this effect goes away if you drink coffee 60 minutes after taking your pills.

So, the answer here is not that you should not consume caffeine, but that you should not consume caffeine too close in time to taking your medication. The recommendation is always to use plain water to wash down your thyroid pills.

This study³ is not as robust as it should be but provides reasonable evidence in this regard. If you take your thyroid medication in the morning, keep them by your bedside and take them as soon as you get up, then wait before having a coffee.

When to talk to a doctor

When diagnosed with Hashimoto's thyroiditis, it is worth asking your doctor about caffeine intake. In most cases, caffeinated beverages will not negatively affect your symptoms and may even be potentially helpful. 

However, your doctor will probably recommend that you enjoy caffeine reasonably (400mg a day or less) and avoid consuming it right after or with your medication.

It's also worth bearing in mind that people have different levels of sensitivity to caffeine. You should take this into account when deciding how much caffeine to consume daily.

The lowdown

If you have Hashimoto's disease, you can absolutely have caffeine. However, you should not use it to self-medicate symptoms (if your symptoms come back, get a blood test and your dosage adjusted).

You should not drink caffeinated beverages within 60 minutes of taking your medication as they may interfere with absorption.

However, if you have an overactive thyroid, you should avoid caffeine since it might worsen symptoms. On the other hand, if you have an underactive thyroid, caffeine will likely provide temporary relief from symptoms.

You should still keep your caffeine consumption at a reasonable level and avoid it late at night as it can cause sleep problems.

Have you considered clinical trials for Hashimoto's disease?

We make it easy for you to participate in a clinical trial for Hashimoto's disease, and get access to the latest treatments not yet widely available - and be a part of finding a cure.

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