Water, alcohol or oil: how an herb’s form changes what you get

Key takeaways

• Europe’s official monograph on lemon balm lists the same leaf five ways, with single doses ranging from about a fifth of a gram of powder to 4.5 grams brewed as tea¹.
• Lemon balm tincture in that monograph is 45% to 53% alcohol, while U.S. rules hold over-the-counter oral medicines labeled for children under 6 to 0.5% alcohol¹⁵.
• Europe’s medicines agency says alcohol-based herbal products should not be used in children under 2 without good reason, and the CDC says no amount of alcohol is known to be safe in pregnancy⁴⁶.
• In the one low-bias trial in a Cochrane review, arnica gel eased hand arthritis about as well as ibuprofen gel over three weeks⁷.
• Fresh garlic or herbs stored in oil can grow botulism toxin, so keep homemade herb oils in the fridge no more than 4 days or freeze them¹¹¹².

Europe’s medicines agency keeps an official monograph for lemon balm leaf, an herb used for mild stress, sleep and an unsettled stomach. It lists five ways to take that one leaf¹.

You can steep 1.5 to 4.5 grams in a cup of boiling water. You can swallow 0.19 to 0.55 grams of powdered leaf. You can take 2 to 6 milliliters of a tincture that is about half alcohol, or a liquid extract, or a dried extract¹.

All five are the same plant. They are not the same dose, and they do not carry the same compounds or the same cautions.

That gap explains a lot. It’s why a cup of tea isn’t the capsule a study tested, and why a tincture needs a second thought for a child or a pregnant woman. It’s also why a jar of garlic in oil on the counter can be more dangerous than any herb in it.

Water, alcohol and oil each pull different things out of a plant

The liquid that draws compounds out of a plant is called the solvent. It decides what ends up in your preparation.

• Water makes teas, cold soaks and compresses. It draws out water-loving compounds. Europe’s monograph on marshmallow root, a soothing remedy for an irritated mouth or throat, relies mostly on water preparations¹⁴. Our companion guide to brewing herbal infusions covers those methods.
• Alcohol mixed with water makes tinctures and liquid extracts. Europe’s medicines agency says alcohol is needed to pull out some plant compounds that matter for the product to work⁴.
• Oil or fat makes infused oils and salves. Europe’s calendula monograph, for example, lists a calendula extract made in olive oil and another made in hardened fat or petroleum jelly⁹.
• Glycerin makes alcohol-free liquids, often called glycerites. None of the European monographs we read for lemon balm, arnica, calendula or marshmallow lists a glycerin preparation¹⁸⁹¹⁴. That means there is no official dose benchmark for most glycerites.

One lemon balm leaf, five official doses

Here is how the European monograph’s single adult doses compare¹. The last column is our own rough math from the stated ratios.

Form	Solvent	Single adult dose	Leaf behind each dose (our estimate)
Tea (infusion)	Boiling water	1.5 to 4.5 g in 150 ml	1.5 to 4.5 g
Powdered leaf	None	0.19 to 0.55 g	0.19 to 0.55 g
Liquid extract, 1:1	45% to 53% alcohol	2 to 4 ml	About 2 to 4 g
Tincture, 1:5	45% to 53% alcohol	2 to 6 ml	About 0.4 to 1.2 g
Dried extract	Water or alcohol	Equal to one of the above	Varies

Three things stand out. A strong cup of tea can involve more leaf than any other form. A powder dose uses the least, perhaps because you swallow all of it. And a tincture dose is a few milliliters of strong alcohol.

The monograph also limits who should use any of them: adults and children over 12 only, and not during pregnancy or breastfeeding, because data are lacking¹. Europe accepts lemon balm under its “traditional use” route, which rests on long use rather than clinical trials, and it opened a periodic review with a call for new data in April 2024. Its page showed no revised monograph when we checked².

Standardized, quantified or neither: what an extract label can tell you

Extracts are where the numbers grow. Europe’s guideline for labeling herbal medicines describes a ginkgo leaf extract made at a ratio of 35 to 67 parts dried leaf for each part of extract³. In plain terms, dozens of kilograms of leaves go into each kilogram of that extract.

That ratio is called the drug-extract ratio, or DER. A “4:1” extract means about 4 units of plant went into 1 unit of extract. A tincture’s ratio is usually written the other way: 1:5 means 1 part plant to 5 parts liquid¹³.

The same guideline sorts extracts into three groups³:

• Standardized. Adjusted to a set amount of compounds known to drive the effect. Senna, for example, is set by its sennoside content.
• Quantified. Blended from batches to land in a range of marker compounds. Willow bark is declared by its salicin content.
• Other. Defined by how it is made, with no marker compound declared.

The guideline also expects European product information to name the extraction solvent and its strength³. If a bottle says “standardized” but won’t tell you the ratio, the solvent or the marker compound, you can’t compare it with a product someone studied.

A capsule of plain powdered herb is a different thing again. It holds the whole plant part, with nothing concentrated or removed, so the amount per capsule is small.

Tinctures carry real alcohol, and that matters for some people

Many tinctures are strong spirits. Lemon balm tincture in the European monograph is 45% to 53% alcohol¹. Europe’s medicines agency has noted that some finished herbal liquids taken by mouth top 60% alcohol⁴.

By our math, one adult lemon balm tincture dose of 2 to 6 milliliters holds roughly 0.7 to 2.5 grams of pure alcohol. That is small for most adults. It is not small for a child.

Children. A 2010 reflection paper from the European Medicines Agency’s herbal committee set out how to limit alcohol in herbal products for kids⁴:

• Avoid alcohol-containing herbal products in babies and children under 2 unless there is a good reason.
• Keep any single dose low enough that a child’s blood alcohol stays under 0.125 grams per liter. For a 6-year-old of about 20 kilograms, that works out to about 1.5 grams of alcohol per dose.
• Space doses at least 4 hours apart, and keep courses short. For children under 6, use beyond a week needs special justification.

In the U.S., a 1995 federal rule limits alcohol used as an inactive ingredient in over-the-counter medicines taken by mouth. The caps are 0.5% for products labeled for children under 6, 5% for ages 6 to 11, and 10% for adults and children 12 and up, with a few exemptions⁵.

That rule is written for over-the-counter drugs. As we read it, it doesn’t reach herbal tinctures sold as dietary supplements, so a tincture that is half alcohol may face no such cap.

Pregnancy. The CDC, in guidance updated in April 2026, says no amount of alcohol has been shown to be safe in pregnancy or while trying to conceive, and no stage of pregnancy is a safe time to drink⁶. The amount in a tincture dose is small, but if you are pregnant, a tea or an alcohol-free form avoids the question. Several European herbal monographs, including those for lemon balm, arnica and calendula, also advise against use in pregnancy because safety data are missing¹⁸⁹.

Medicines and recovery. Europe’s committee notes that alcohol can strengthen the effect of sedatives, change how the liver clears some drugs, and set off a disulfiram-like reaction with some antibiotics⁴. Disulfiram is a medicine that makes drinking alcohol unpleasant. Ask a pharmacist before pairing any tincture with a prescription.

The same paper warns that regular exposure to alcohol can lead to dependence, and it asks that herbal medicines state how much alcohol they contain⁴. If you avoid alcohol for any reason, including recovery from alcohol use disorder, check the label and choose a tea, a capsule or an alcohol-free form.

Creams, gels and compresses: what the skin trials show

Herbs for the skin come in many forms: compresses soaked in warm tea, salves made with fat, and gels or creams made from tinctures. Here the evidence is thin but not empty.

A Cochrane review, a careful summary of the best trials, looked at herbal products rubbed on the skin for osteoarthritis. It found 7 trials with 785 people, each testing a different product⁷. That makes firm conclusions hard.

Use	What the research shows	Rating
Arnica gel for hand arthritis	One trial of 204 people found it about as good as ibuprofen gel over 3 weeks; side effects 13% vs. 8%7	Promising but early
Comfrey ointment for knee arthritis	One trial of 220 people found less pain than with a placebo cream7	Promising but early
Hot pepper (capsicum) extract gel for knee arthritis	One trial of 99 people found no more relief than placebo; 80% had side effects, mostly burning, vs. 20%7	Evidence says no, at the doses tested
Calendula for minor skin irritation and small wounds	Europe accepts it on long traditional use, not trials9	Not enough evidence
Arnica for bruises and sprains	Europe accepts it on long traditional use8	Not enough evidence

The arnica trial was the only study in the review judged at low risk of bias on every measure⁷. The gel tested was a commercial product from the maker A. Vogel. According to details the company gave the reviewers, it was made from a tincture prepared with 50% alcohol⁷. Neither the review nor any page we could open said who paid for the trial.

Two cautions travel with these products. Arnica and comfrey are meant for the skin only⁷. Europe’s arnica monograph lists only skin use and says not to put it on broken skin⁸.

The hot pepper result applies only to that extract gel. The review left out trials of capsaicin, the pure heat compound sold in over-the-counter pain creams⁷¹⁰.

Daisy allergies and burns: test a skin product first

Arnica and calendula belong to the daisy family, also called Asteraceae. Europe’s monographs say not to use either if you’re allergic to plants in that family, and both list allergic skin reactions as possible side effects⁸⁹.

Over-the-counter rubs can burn. In 2012, the FDA said it had found 43 reports of burns where people applied store-bought muscle and joint rubs made with menthol, methyl salicylate or capsaicin¹⁰. Most of the serious burns involved menthol, and only a few involved capsaicin. Many followed a single use, sometimes within a day¹⁰.

The FDA’s advice applies to herbal rubs, too¹⁰:

• Keep them off wounds and off skin that is broken, damaged or irritated.
• Don’t wrap the area tightly or add a heating pad or other heat source.
• Keep products away from your eyes and from moist inner tissues, such as the inside of the mouth or nose.
• Stop and get care for pain, swelling or blistering.

Because both monographs list allergic skin reactions⁸⁹, try a simple check before regular use: put a small dab on the inside of your forearm and watch the spot for a day or two. Europe’s calendula monograph also offers a gentle compress method: steep 1 to 2 grams of flowers in 150 milliliters of water, soak a cloth in the liquid, and remove it after 30 to 60 minutes⁹. It isn’t recommended for children under 6⁹.

The tool: compare forms before you buy or make one

Shelf life depends on the product, so follow the label unless you made it yourself.

Form	What it carries	Typical use	Storage	Safety notes
Tea or cold soak	Water-soluble compounds	Gentle daily use	Make fresh; use a soak right after making it14	Strength varies with amount and steep
Powdered herb capsule	The whole plant part	Matching a traditional dose	Follow label date	Small amount per capsule
Tincture or liquid extract	Water- and alcohol-soluble compounds	Small, portable doses	Follow label date	Alcohol: children, pregnancy, medicines46
Standardized dried extract	A concentrate set to a marker	Matching a studied product	Follow label date	Far stronger than tea; check ratio and solvent3
Infused oil or salve	Fat-soluble compounds	Skin, massage, cooking	Homemade: fridge up to 4 days, or freeze12	Botulism risk with fresh garlic or herbs11
Gel, cream or compress	An extract or tincture in a base	Bruises, sore muscles, minor skin irritation	Follow label date	Patch-test; never on broken skin810

Essential oils are a separate, far more concentrated form. Our article on lavender and sleep covers them.

Which form fits your goal?

• You want the gentlest, most traditional route. Start with tea. Drink it the way the tradition does.
• You want what a study tested. Buy the exact extract, with the plant part, ratio, solvent and marker named on the label³.
• You avoid alcohol, are pregnant or are dosing a child. Choose tea, a powder capsule or a labeled alcohol-free form, and ask your clinician first⁴⁶.
• You have a bruise or sore muscle on unbroken skin. An arnica gel or cream is a traditional choice, for the skin only⁸.
• You want to make an herb oil. Make a small batch, keep it cold and use it fast, or freeze it¹¹¹².

Respecting the old forms means respecting their limits

Every form in this guide began as a kitchen or apothecary skill: steeping, soaking in spirits, warming plants in fat. Europe’s herbal monographs still list many of these preparations, each paired with an age limit and a warning¹⁸⁹.

That pairing is a good model. Self-reliance means knowing that a teaspoon of tincture, a capsule and a cup of tea are three different decisions, and choosing the one that fits your body, your family and your medicines.

When to get help

Stop a skin product and see a clinician if a rash spreads, blisters form or a wound shows signs of infection⁹¹⁰. Europe’s monographs suggest seeing a doctor if a bruise or sprain isn’t better in 3 to 4 days, or skin irritation lasts beyond a week⁸⁹.

If a child swallows a tincture or any herbal product, call Poison Help at 1-800-222-1222¹³. Call 911 if anyone collapses, has a seizure, has trouble breathing or can’t be woken¹³. Our article on respecting nature lists the warning signs of botulism.

Questions readers ask

The bottom line

The form of an herb is part of its dose. Water, alcohol and oil each pull out different compounds, and the same leaf can mean very different amounts depending on whether you brew it, swallow it or rub it on.

Choose the form on purpose. Use tea when you want gentle, read extract labels for ratio and solvent, keep alcohol-based tinctures away from babies and out of pregnancy, test creams on a small patch first, and never store fresh garlic or herbs in oil at room temperature.

Related reading

• How to brew herbal infusions safely and well, including the herbs that need cold water
• How to judge a cup of herbal tea, which is gentle but not automatically harmless
• Herbal supplements are a $13 billion business, and herbalists need no license
• Nature makes both medicine and deadly poison, and respecting it means telling them apart
• Lavender is the best-studied sleep scent, though its trials can’t hide the smell

Sources

1. European Medicines Agency, Committee on Herbal Medicinal Products. “Community Herbal Monograph on Melissa officinalis L., folium.” EMA/HMPC/196745/2012, May 14, 2013 (copy hosted by e-lactancia.org). e-lactancia.org
2. European Medicines Agency. “Melissae folium: Herbal Medicinal Product.” EMA, last updated April 2, 2024. ema.europa.eu
3. European Medicines Agency, Committee on Herbal Medicinal Products. “Guideline on Declaration of Herbal Substances and Herbal Preparations in Herbal Medicinal Products/Traditional Herbal Medicinal Products.” EMA/HMPC/CHMP/CVMP/287539/2005 Rev.1, 2010. ema.europa.eu
4. European Medicines Agency, Committee on Herbal Medicinal Products. “Reflection Paper on Ethanol Content in Herbal Medicinal Products and Traditional Herbal Medicinal Products Used in Children.” EMA/HMPC/85114/2008, adopted January 14, 2010. ema.europa.eu
5. U.S. Code of Federal Regulations. “21 CFR 328.10: Alcohol (OTC Drug Products Intended for Oral Ingestion That Contain Alcohol).” eCFR, current as of October 2026. ecfr.gov
6. Centers for Disease Control and Prevention. “About Alcohol Use During Pregnancy.” CDC, updated April 2, 2026. cdc.gov
7. Cameron M, Chrubasik S. “Topical Herbal Therapies for Treating Osteoarthritis.” Cochrane Database of Systematic Reviews, 2013 (CD010538). pubmed.ncbi.nlm.nih.gov
8. European Medicines Agency, Committee on Herbal Medicinal Products. “Community Herbal Monograph on Arnica montana L., flos.” EMA/HMPC/198793/2012, adopted May 6, 2014 (copy hosted by e-lactancia.org). e-lactancia.org
9. European Medicines Agency, Committee on Herbal Medicinal Products. “European Union Herbal Monograph on Calendula officinalis L., flos, Revision 1.” EMA/HMPC/437450/2017, adopted March 27, 2018. ema.europa.eu
10. U.S. Food and Drug Administration. “FDA Drug Safety Communication: Rare Cases of Serious Burns With the Use of Over-the-Counter Topical Muscle and Joint Pain Relievers.” FDA, September 13, 2012.
11. Nummer BA, Schaffner DW, Fraser AM, Andress EL. “Current Food Safety Issues of Home-prepared Vegetables and Herbs Stored in Oil.” Food Protection Trends, 2011;31(6):336–342. foodprotection.org
12. Oehler N. “Guidelines for Refrigeration of Foods.” Oregon State University Extension Service, SP50-677, revised July 2024. extension.oregonstate.edu
13. America’s Poison Centers. “Poison Help.” poisonhelp.org, accessed October 2026. poisonhelp.org
14. European Medicines Agency, Committee on Herbal Medicinal Products. “European Union Herbal Monograph on Althaea officinalis L., radix.” EMA/HMPC/436679/2015, adopted July 12, 2016. ema.europa.eu