Frangula.
Aged alder buckthorn bark works overnight on regularity. Colonic bacteria convert it into the active form, which speeds movement through the colon and shifts water into the bowel.
- Category
- Herb
What Frangula is, and what it does.
- Does it work
- Suits adults who want short-term occasional help with regularity. Monographs keep anthranoid herbs to brief runs, so it works as an occasional tool rather than a daily fixture.
- How much to take
- No amount is on record here. Monograph practice is the smallest amount that produces a soft stool, taken at night. Start with the label of a standardised preparation.
- Time to feel it
- Overnight. Six to twelve hours between the dose and the effect, because it has to reach the colon and be converted by bacteria before anything happens.
- The first dose
- You take it in the evening and the effect lands next morning. A bigger amount makes it stronger rather than faster, and can bring cramping with it.
- With regular use
- It is built for short runs. Monograph guidance keeps anthranoid use to about a week at a time, with a doctor involved beyond that.
- How well tolerated
- Cramping and loss of fluid or potassium are the practical concerns. Not for children, pregnancy or breastfeeding, and check with a doctor if you take anything affecting potassium.
- How it feels
- Nothing in the evening. Some gurgling or mild cramping toward morning, then a soft and fairly urgent bowel movement.
- The overlooked benefit
- The year of ageing is not folklore. Fresh bark carries reactive anthrones that cause violent vomiting, and storage oxidises them into the gentler glycosides.
The proof, claim by claim.
These words describe the research, not the molecule's worth. Research strength is how much work stands behind one claim, and it is never a product score.
- bowel regularityRandomised trial
- colonic motility and luminal water shiftNarrative review
- bacterial conversion of glycosides to the active anthroneNarrative review
- short-term use limits for anthranoid preparationsNarrative review
Why these belong in the same formula. Each row says what the basis is, from settled biochemistry through to a trial that measured the pair.
Glucofrangulins A and B pass the small intestine largely unabsorbed. Colonic bacteria remove the sugars and reduce emodin to its anthrone form, which is the active species. Bacterial capacity therefore sets how much of a given dose does anything. This is the same conversion step the whole anthranoid class depends on.
More luminal water and faster transit mean the colon reclaims less potassium. Single occasional use is not where this shows up. Repeated use over weeks is. Blood potassium is a laboratory measure, not something noticed early. This is a central reason the class is positioned for short courses.
Magnesium salts at laxative doses draw water into the lumen while frangula anthranoids act on motility and secretion. The two stack rather than balance. Magnesium taken for other reasons at ordinary supplemental doses sits well below the laxative range, so the concern is specific to high-dose magnesium salts. Fluid and electrolyte shifts compound in the same way.
Psyllium adds stool mass and holds water mechanically, and it holds up over long periods without adaptation. Frangula acts on the enteric nervous system and is built for short use. Fibre as the base with the stimulant reserved for occasional use is the conventional structure. Taken simultaneously they are hard to titrate apart.
Glycyrrhizin increases renal potassium excretion by letting cortisol act at the mineralocorticoid receptor. Anthranoids increase faecal potassium losses. The additive risk is easy to overlook because the two sit in different product categories. Deglycyrrhizinated licorice does not carry it.
Non-heme iron uptake in the duodenum depends on residence time and local pH. Anything accelerating transit narrows that window. The direction follows from mechanism. The magnitude in intermittent use has not been quantified. Separating iron dosing from laxative timing settles the question without needing the number.
Cramping is the usual complaint with anthranoid laxatives, and menthol relaxes intestinal smooth muscle through calcium channel effects. Herbal laxative teas conventionally include a carminative for this reason. The pairing is practice with a plausible mechanism rather than a tested combination. It does not affect how much anthranoid gets converted.
Nothing specific on file for Frangula. Match the label to the daily amount above, and tell your doctor what you take.
Not medical advice. Show the label to your pharmacist.What Frangula actually does.
Frangula bark carries anthraquinone glycosides as its characteristic compounds, and these are the basis for how it's standardized.
These glycosides are too polar to be absorbed intact and travel to the colon, where bacteria strip off the sugars and convert what's left into the active form.
That active form speeds up colon muscle contractions and shifts the balance of water and salts toward the gut, the same mechanism as other laxative herbs in this family.
The delay between taking it and feeling an effect, usually overnight, reflects the time needed to reach the colon plus the time bacteria take to convert it, a higher dose makes the effect stronger without making it happen sooner.
Where Frangula comes from.
Bark from the alder buckthorn shrub, used as a laxative for centuries. The bark has to be aged at least a year before use, because fresh bark makes people violently sick. Once aged, gut bacteria convert it overnight into the form that actually works.
Made from a plant. What ends up in the capsule tracks the harvest, so batch testing and a stated marker matter more here than with a made molecule.
Bark of alder buckthorn, stripped from stems and branches, traditionally in spring when it separates cleanly.
The critical step. Fresh bark contains free anthrones that cause violent gastrointestinal effects. A year of dry storage, or a validated heat treatment, oxidises them to anthraquinone glycosides.
The glycosides are polar and partition into aqueous or dilute alcohol solvent.
Pharmacopoeial material is assayed spectrophotometrically or by HPLC and expressed against glucofrangulin A.
Supplied as tea-cut bark, a hydroalcoholic fluid extract, or a dry extract blended to a declared percentage.
The forms it comes in.
The studies, linked.
1 source behind our Frangula verdict: peer-reviewed studies and registered clinical trials. Every one links straight to PubMed, the journal, or ClinicalTrials.gov. Read them yourself.
- Clinical trialRandomized Clinical Trial of Triptolide Woldifii for Autosomal Dominant Polycystic Kidney Disease (ADPKD)ClinicalTrials.gov ↗300 participants, Terminated
Evidence surfaced via Semantic Scholar (Allen Institute for AI) and ClinicalTrials.gov. Ranked by study type and citation weight, not cherry-picked.
Problems people have reported.
Read this carefully. These are 14,443 voluntary, unverified reactions reported to the FDA (openFDA). The number mostly reflects how popular Frangula is, not how risky it is. A report is not proof Frangula caused anything. It is a signal of what to watch for, nothing more.
Source: openFDA adverse-event reports. Voluntary reporting, not an incidence rate.
FDA Disclaimer: These statements have not been evaluated by the Food and Drug Administration. This information is for educational purposes only and is not intended to diagnose, treat, cure, or prevent any disease. Consult your healthcare provider before starting any supplement regimen.