Mullein Tea: The Official Dose Is for the Flower, Not the Leaf

Reviewed by the HealthyMag Editorial Team. Every figure below is quoted from the European Union herbal monograph, read on 13 September 2026.

Mullein tea is one of those things people drink for a reason they picked up secondhand. The reason usually involves lungs. The only official document that exists on the subject says something narrower, more specific, and more useful than anything on the packet.

The document, and what it covers

The European Medicines Agency’s Committee on Herbal Medicinal Products publishes monographs on plants used medicinally in the EU. These are not marketing. They are the reference EU member states use when deciding whether a herbal product may be licensed, and they are written in the same structure as a drug label: indication, dose, duration, contraindications, warnings.

Mullein has one, adopted on 27 March 2018. Its title names three species — Verbascum thapsus L., V. densiflorum Bertol. and V. phlomoides L. — followed by one word that decides everything: flos.

Flos is the pharmacopoeial term for flower. The monograph is about mullein flower.

Now look at what is on sale. Search for mullein tea in the United States and you will be offered mullein leaf, over and over, in bags and in loose cut. The leaf is what the American market sells. The flower is what Europe’s regulator assessed.

That is not a scandal and it does not make leaf tea harmful. It does mean that if you bought your tea because it is “traditionally used”, the tradition that got written into a regulatory document is about a different part of the plant.

The dose, as published

This is the part we could not give you on our page about mullein and lungs, because for lungs no dose exists. For the flower as a tea, one does. Quoted from the monograph:

Three to four cups a day is more than most people drinking it casually, and 1.5 to 2 g is a generous teaspoon rather than a pinch. If you have been having one weak cup and wondering why nothing happens, the monograph’s answer is that you are below the traditional dose it describes.

The indication is narrower than the marketing

Here is the indication in full, as written:

Traditional herbal medicinal product used to relieve symptoms of sore throat associated with dry cough and cold.

Read what is in that sentence and what is not. It is about the throat. It specifies a dry cough, not a productive one. It ties the whole thing to a cold, meaning a short, self-limiting illness.

What is absent: lungs, mucus clearance, detoxification, smoking recovery, congestion, asthma, COPD. None of those made it into the document, and they are most of what mullein is sold for.

The two columns, and why the empty one matters

EU monographs are laid out in two columns: well-established use and traditional use. The first is for indications supported by clinical evidence. The second is for indications supported by the fact that people have been doing it for a very long time — the threshold is 30 years of medicinal use, of which at least 15 in the EU.

In the mullein monograph, every clinical entry sits in the traditional use column. The well-established use column has nothing in it.

That is the regulator telling you, in its own formal language, exactly what our review of the literature found independently: there is no trial evidence here. What there is instead is centuries of consistent use for a specific, modest purpose, documented carefully enough to write a dose against.

Traditional use is a real category and it is not an insult. It is simply a different claim from “this was tested and it worked”, and the monograph never pretends otherwise.

The instructions everybody leaves out

Three lines from the same document that we have not seen on a single tea page:

• Stop at one week. If the symptoms persist longer than 1 week during the use of the medicinal product, a doctor or a qualified health care practitioner should be consulted. A sore throat that outlasts a week is not a tea problem.
• Not for children under 12. The use in children under 12 years of age has not been established due to lack of adequate data. Note the reason: not a known harm, an absence of data.
• If it gets worse, see someone. The monograph says so explicitly for symptoms that worsen during use.

The one-week limit is the most useful sentence in the document, because the failure mode with herbal tea is not toxicity. It is spending three weeks drinking something soothing while an infection that needed treatment gets on with it.

Straining is not optional

One practical point the monograph does not cover, because it assumes a pharmaceutical-grade preparation, and home tea is not that.

Mullein leaves and flowers are covered in fine hairs. In loose home preparations those hairs pass straight through a coarse mesh infuser and into the cup, where they irritate the mouth and throat. That is the precise opposite of the effect you are drinking it for.

Strain through a paper filter, a cloth, or a very fine mesh. If the tea is scratchy going down, the straining rather than the plant is the problem. This is also the main practical argument for tea bags or a liquid extract over loose flower: both remove the step people skip.

Flower or leaf, in practice

We are not going to tell you leaf tea is worthless, because nobody has compared them in a trial and we do not know. What we can say is what each one has behind it:

• Flower. An EU monograph, a stated dose, a stated indication, a stated duration and an age limit. All resting on traditional use rather than trials.
• Leaf. Long folk use, a great deal of marketing, and no monograph.

If you want the version with a document behind it, buy flower and follow the numbers above. If you already have leaf tea in the cupboard, drinking it for a scratchy throat is a reasonable, low-risk thing to do — just do not expect it to do anything for your lungs, because nothing in the evidence suggests it will.

Frequently Asked Questions

What does mullein tea actually do?

According to the only official assessment of it, the EU herbal monograph adopted in March 2018, it is a traditional herbal medicinal product used to relieve symptoms of sore throat associated with dry cough and cold. That is the whole approved claim. It is a soothing preparation for an irritated throat during a cold, and it sits in the monograph’s traditional-use column, which means the basis is long-standing use rather than clinical trials.

How much mullein tea should I drink a day?

The monograph gives a single dose of 1.5 to 2 g of the herbal substance in 150 ml of boiling water as an infusion, taken three to four times daily, for a daily dose of 4.5 to 8 g. That is more than most casual drinkers take. It applies to the flower, which is what the monograph covers, and it is intended for adolescents, adults and the elderly.

Can I drink mullein tea every day?

The monograph does not describe it as a daily long-term drink. It describes a short course for a specific complaint, and it attaches a limit: if symptoms persist longer than one week during use, consult a doctor or qualified health care practitioner. So the honest answer is that daily use for a week during a cold is what the document supports; indefinite daily use for general wellbeing is not something anyone has assessed.

Who should not drink mullein tea?

The monograph lists hypersensitivity to the active substance as the contraindication, and states that use in children under 12 has not been established due to lack of adequate data. Anyone whose symptoms are worsening should see a clinician rather than continue. As with any herbal preparation taken alongside prescription medication, clear it with whoever writes your prescriptions first.

What are the side effects of mullein tea?

The commonest complaint is not really a side effect of the plant at all: it is throat and mouth irritation from the fine hairs on the leaves and flowers passing through a coarse strainer. Strain through paper or cloth and it goes away. Beyond that, because the monograph rests on traditional use rather than trials, there is no trial-grade side-effect table for mullein, which is worth knowing in both directions.

Is mullein flower or mullein leaf better for tea?

Nobody has compared them head to head, so “better” cannot be answered. What can be answered is which has documentation: the EU monograph covers the flower, Verbasci flos, and gives it a dose, an indication, a duration and an age limit. The leaf has folk use and marketing but no monograph. Most mullein tea sold in the United States is leaf.

Does mullein tea help your lungs?

Not according to any evidence we can find, and notably not according to the monograph, whose indication stops at the throat. We searched PubMed for a human trial of mullein for cough or lungs and found none; the one randomised controlled trial of Verbascum thapsus in the index is about episiotomy wound healing. Our full review of that literature is linked below.

How do you make mullein tea properly?

Following the monograph: 1.5 to 2 g of the dried flower in 150 ml of boiling water, infused, up to three or four times a day. Then the step it does not mention because it assumes a pharmaceutical preparation — strain it through paper or cloth rather than a coarse mesh, because the plant’s fine hairs will otherwise irritate the throat you are trying to soothe.

The Bottom Line

There is exactly one official document on mullein in the world, and it is more specific than anything written to sell the stuff. It covers the flower rather than the leaf. It gives a genuine dose — 1.5 to 2 g in 150 ml, three to four times a day. It limits the claim to a sore throat with a dry cough during a cold. It tells you to stop after a week and see someone. And it places the whole thing in the traditional-use column, which is the regulator’s honest way of saying nobody ran the trials.

Drink it for a scratchy throat with the numbers above and you are doing something modest, cheap and supported by a real document. Drink it to clean your lungs and you are doing something nobody has any evidence for.

Sources

1. European Medicines Agency, Committee on Herbal Medicinal Products (HMPC). European Union herbal monograph on Verbascum thapsus L., V. densiflorum Bertol. (V. thapsiforme Schrad) and V. phlomoides L., flos. EMA/HMPC/611537/2016, adopted 27 March 2018 — herbal tea posology “1.5-2 g of the herbal substance or the comminuted herbal substance in 150 ml boiling water as a herbal infusion three to four times daily. Daily dose: 4.5-8 g”; indication “Traditional herbal medicinal product used to relieve symptoms of sore throat associated with dry cough and cold”; “The use in children under 12 years of age is not recommended”; “If the symptoms persist longer than 1 week during the use of the medicinal product, a doctor or a qualified health care practitioner should be consulted”; contraindication “Hypersensitivity to the active substance”; all clinical entries in the traditional-use column. Monograph PDF. Checked 13 September 2026.
2. European Medicines Agency, Verbasci flos — herbal medicinal product — the HMPC’s published conclusion that mullein flower medicines can be used for relief of sore throat associated with dry cough and cold, in adults and adolescents over 12. ema.europa.eu. Checked 13 September 2026.
3. HealthyMag, Mullein for Lungs: The One Trial Is About Something Else — our PubMed search for human trials of mullein for cough or lungs, which returned none, and the American Lung Association’s position on lung “detox” products. healthymag.org. Checked 13 September 2026.