Herbal preparations

Herbal preparation is the craft of getting something out of a plant and keeping it. That is genuinely all it is at the level this page works at: you have plant material, you want the parts of it that dissolve, and you want what you end up with to still be good in six months. Water, alcohol, oil, heat and time are the whole toolkit.

It is an old craft, it is closely tied to growing and to foraging, and it has a large and enthusiastic literature almost none of which is written to the standard this catalogue applies. That is the defining problem of the subject and the reason this page is shaped the way it is. The overwhelming majority of what you will find is written to persuade you that a preparation treats something, and this page makes no statement of that kind about anything, in either direction.

What it does instead is cover the parts that are real and checkable: what the forms are and what distinguishes them, why the solvent changes what you extract, how drying and storage decide whether the work was worth doing, and where the law sits — which turns out to be the most surprising section on the page.

What this page is

A craft and legal orientation

What it is not

A health page, in any part

The whole toolkit

Water, alcohol, oil, heat, time

Hardest part

Identification, which it does not answer

1. 1

   Step 1: Start with bought dried material, not with gathering

   It removes the identification problem entirely for as long as you want it removed, it is cheap, and it lets you learn the craft — drying, extracting, straining, storing — without the hardest and highest-consequence part attached to it.

   You will know it worked when: The craft, without the identification risk.

2. 2

   Step 2: Learn to dry and store before learning to extract

   This is the reverse of how it is usually taught and it is the right order. Drying and storage decide the quality of everything afterwards, they are entirely safe to practise, and they are where the craft actually lives.

   You will know it worked when: Material that is still good in six months.

3. 3

   Step 3: Make something external first

   An infused oil and a simple salve are the whole process in miniature — extract, strain, store — with nothing consumed at the end of it. It is the cleanest way to learn the mechanics.

   You will know it worked when: A finished thing, and the process understood.

4. 4

   Step 4: Label everything from the first jar

   Establish the habit while you have three jars rather than discovering the need at thirty. What, which part, from where, in what, when.

   You will know it worked when: A shelf you can still read next year.

5. 5

   Step 5: If you want to gather, learn identification separately and properly

   From a botanical society, a local group or a qualified teacher, as its own skill with its own timeline — not from this page, not from an app, and not as a step in a recipe. Growing what you want to use sidesteps it almost entirely and is what a great many people do.

   You will know it worked when: Identification treated as the skill it is.

6. 6

   Step 6: Read the legal section before making anything for anybody else

   The answer is more restrictive than most people assume, and the restriction is the point at which a private craft becomes a regulated activity.

   You will know it worked when: A clear idea of where the boundary is.

The one genuinely technical idea in this craft, and it is chemistry rather than herbalism: different solvents dissolve different things, so the choice of what you steep a plant in decides what you get out of it and how long it keeps. Everything below is about that and stops there. No ratios, times or yields are published on this page.

• Water extracts what is water-soluble, and keeps badly — Sugars, some acids, tannins and mucilage come out readily in water. The trade-off is preservation: a water extract is a nutrient broth at room temperature and spoils in days, which is why infusions are made fresh and why every other form on this page exists.
• Alcohol extracts more, and preserves — Alcohol dissolves resins, some oils and a range of compounds water leaves behind, and at sufficient strength it prevents microbial growth. That combination — pulls out more, keeps for years — is the entire reason the tincture is the classic form. It is also why the strength of the spirit matters more than any other variable in the process.
• Oil extracts what is oil-soluble, and hates water — Fixed oils take up the oil-soluble fraction and nothing else, which makes them selective. The failure mode is specific and universal: any water left in the plant material will spoil the oil from the inside, which is why oil infusions are made from properly dried material and why a mouldy jar of oil is almost always a drying failure rather than a technique one.
• Vinegar and glycerol are the alternatives, with trade-offs — Both extract a narrower range than alcohol and preserve less well, and both exist mainly because they avoid alcohol. Worth knowing as categories because a lot of writing treats them as straight substitutions, and they are not.
• Fresh against dried is a real decision, not a preference — Fresh material brings its own water with it, which dilutes an alcohol extract and ruins an oil one. Dried material does not, but has lost the volatile fraction. Which is appropriate depends on the form and on the plant, and it is the point at which somebody moves from following instructions to understanding them.

• Dark glass, in small sizes — The highest-value purchase in the craft and the one beginners skip. Light degrades stored preparations, air degrades them faster, and a large part-empty bottle is mostly air. Small dark bottles and jars, £15–£40 for a working set, and they last indefinitely.
• A scale reading to 0.1g — £15–£25. Not for any published quantity — this page publishes none — but because a craft you cannot repeat is not a craft. Recording what you did is what turns a lucky result into a method.
• Muslin, a fine sieve and a large funnel — A few pounds. Straining is the messiest step and the one where the most is lost; a press is a genuine upgrade later and is not needed at all to start.
• Somewhere dark, dry and airy to dry material — A rack in a spare room does it. A low-temperature dehydrator at £40–£120 does it faster and more reliably, and is worth it only if you are drying in quantity or in a damp house.
• Labels, and more of them than you think — The cheapest item and the one that decides whether the shelf is an asset or a liability in a year. See the storage section.
• What you do not need — A still, a press, a vacuum anything, or a cupboard of specialist equipment. This is a craft whose ceiling is reached with jars.

The craft ceiling here is lower than the subject’s reputation suggests, and that is a feature. Within a year of steady practice somebody is drying reliably, extracting into all the common solvents, keeping a usable record and getting consistent results — which is most of what there is at this level.

Depth after that goes in one of three directions. Growing is the commonest: a garden planted for this purpose, which is a large and satisfying project and hands the interesting problems to horticulture. Making is the second: soap, cosmetics, dyeing and scent all take infused oils and extracts as inputs, and all have more craft ceiling than this does. The third is clinical practice, which is a trained profession with registers, a consultation model and a legal position of its own, and it is entered through training rather than through hobby practice. This page is not a route into it and does not pretend to be.

• Identification is the risk, and it is not answered here — Every other hazard in this craft is downstream of knowing what you actually picked. This page publishes no identification key, no distinguishing feature and no test, for the same reason the mycology page publishes no edibility claim for any species: identification and safety are separate questions, and a partial answer to the first reads as an answer to the second. If material is gathered rather than bought, the identification belongs to a competent local source — a botanical society, a qualified forager, a herbarium — and not to a website.
• Concentration is the thing that makes preparation different from cooking — An extract is not the plant. It is a selected fraction of it, in a smaller volume, and the whole point of the craft is that it is more concentrated than what you started with. That is worth stating plainly because it is the assumption most often missing when people reason from "it is only a plant" or from having eaten something in a salad.
• Alcohol is a real hazard on its own terms — High-strength spirit is flammable, it is harmful to swallow in quantity irrespective of what is in it, and it needs storing accordingly and out of reach of children. This is the one safety point on the page that has nothing to do with plants.
• Anything made for somebody else changes the question completely — The moment a preparation is made for another person, this stops being a private craft and enters a regulated space — see the legal section. This page is written for somebody making things for themselves.
• What to do if something goes wrong — Treat suspected poisoning as an emergency and seek medical help immediately rather than looking anything up. Take the plant material or the container with you if you can; what was taken is the first question that will be asked and the hardest to answer afterwards, which is one more argument for labelling everything.

Making preparations from plants for your own use is not a regulated activity in the United Kingdom. Almost everything else about this subject is, and the shape of that regulation explains several things that otherwise look arbitrary — including why the shelf in the health food shop looks the way it does.

This section is a summary of three provisions and is not legal advice. Where it matters, the regulator is the MHRA and the legislation is named so it can be read directly.

• A "Traditional Herbal Registration" does not mean it works — This is the single most useful fact on the page and it surprises nearly everybody. A THR is granted on evidence of traditional use, not efficacy. The applicant must show the product "has been traditionally used to treat the stated condition for a minimum of 30 years", of which "at least 15 years of the 30 years of use must relate to use in the EU/EEA", and the evidence supplied relates to "the safety, quality and traditional use of the herbal product". Its scope is bounded too: a THR "is only granted if the medicine is used for minor health conditions where medical supervision is not required (e.g. a cold)", and anything claiming to treat major conditions needs a full marketing authorisation instead. So the THR number on a box tells you the product is made to a quality standard and has a long history of use. It does not tell you it does anything.
• Some herbal ingredients are restricted by law — There is a published list of "herbal ingredients which are subject to various restrictions in the UK", maintained by the regulator and changing over time. The restrictions are of several kinds. The Medicines (Aristolochia and Mu Tong etc.) (Prohibition) Order 2001 prohibits manufacturing or supplying unlicensed medicines containing certain plants outright. Aconite — all *Aconitum* species — carries "No permitted dose unless made available by a prescription". Kava-kava is "Not permitted in unlicensed medicines, except those exclusively for external use". Ephedra is capped by dose and "can only be sold in premises which are registered pharmacies and by or under the supervision of a pharmacist". These are named here as legal facts, and this list is not a guide to which plants are harmful.
• The practitioner exemption is narrow, and it explains the whole retail picture — Regulation 241 of the Human Medicines Regulations 2012 exempts a herbal practitioner from the usual licensing requirements, but only where four conditions are all met: the product contains nothing from Part 1 of Schedule 20 and respects the limits for Part 2; the transaction happens "on premises occupied by A and from which A can exclude the public"; and it is for a specific person who has "requested by or on behalf of B and in B’s presence" that the practitioner "use A’s judgment as to the treatment required". A one-to-one consultation, in person, on the practitioner’s own premises. Nothing about that permits selling over a counter or online, which is exactly why you do not see it.
• Selling anything you make is a different activity — The moment a preparation is supplied to somebody else, medicines law, food law or cosmetics law applies depending on what it is and what is said about it — and what is *said about it* is frequently what decides which. Making a health claim is itself the regulated act. This page covers a private craft and does not attempt the commercial route.
• Gathering has its own rules, and they are not these — Where you may pick, what you may pick and whose land it is are separate questions governed by access and conservation law rather than by medicines law. They are covered in the foraging part of the catalogue.

This is the least glamorous part of the subject, the part almost no other source covers, and the part that separates a shelf of things you can use from a shelf of things you are guessing about. It also carries no health question at all, which is why it can be written here in full.

• Dry thoroughly, or accept everything downstream will fail — Incomplete drying is the root cause of most spoiled preparations, and it is invisible until it is not — material can feel dry and still hold enough water to sour an oil or grow mould in a jar. Dry in the dark, with air moving, and store only when it is brittle rather than merely limp.
• The four enemies are light, air, heat and moisture — In roughly that order for dried material and stored extracts alike. Dark glass, filled containers, a cool cupboard and thorough drying address all four, and nothing else you do compensates for getting them wrong.
• Label at the moment of making, never afterwards — What it is, which part of the plant, where it came from, what it was extracted into, and the date. A shelf of unlabelled jars is worthless within a year and is a genuine hazard rather than merely an annoyance, because the one question anybody will ask about an unlabelled preparation is the one you cannot answer.
• Keep a book, not a memory — Batch, date, source of material, what you changed. This is the record-keeping half of the craft and it is the thing that lets you improve rather than repeat. It is also what makes an unexpected result diagnosable rather than mysterious.
• Expect dried plant material to fade rather than to spoil — Properly dried and properly stored material generally loses character gradually rather than going off at a point, which is why a date on the label matters more than a rule about shelf life. Colour and smell going flat is the usual signal that a batch has stopped being worth using.
• Throw away anything you are unsure about — The economics of this craft are on your side — the material is cheap or free, the containers are the expensive part and they are reusable. There is never a good reason to keep a jar you cannot identify or that looks wrong.

• Growing your own — The most common route in and the one that removes the identification problem at source, because you know what you planted. The cultivation depth belongs to the growing side of the catalogue rather than here.
• Foraging — The other route in, and the one that carries the identification risk this page declines to answer. Access rights, conservation restrictions and what may lawfully be picked are covered there.
• Botanical spirit blending — The immediately adjacent craft and a much simpler one — the same maceration of botanicals in alcohol, aimed at flavour rather than at anything else, with no health question anywhere near it. If what appeals here is the extraction and the recipe design, that page is the same pleasure with none of the boundary.
• Natural dyeing — The same plants, the same extraction, an entirely different output. Frequently the same people.
• Soap and cosmetics making — Where infused oils most often end up, and a craft with its own regulatory position once anything is supplied to another person.
• Clinical herbal medicine, which is not this — A trained practice with professional registers, a consultation model and the regulation 241 exemption behind it. It is a different thing from the craft on this page, it is not learned from a website, and this page is not a route into it.