# Bitter aloes (Aloe vera)

**Aloe*, Socotrine aloes*

**Known today as.** The dried juice of *Aloe vera*, *A. ferox*, and *A. perryi* of Socotra.

Kind: Plant  
Qualities: Hot and dry (Galenic tradition).  
Toxic: yes

> **Caution.** A harsh laxative; not for pregnancy.

## What was it used for?

The great purge of the old pharmacy, the base of [hiera picra](https://thethinkingpress.org/materia-medica/hiera-picra); not the aloe of Scripture (see [Aloe](https://thethinkingpress.org/materia-medica/aloe)).

## What does modern science say?

A strong anthraquinone laxative; the United States removed it from over-the-counter laxatives in 2002.

## Pharmacognosy and toxicology

- **aloin**: barbaloin
- **aloe-emodin**: 

**Mechanism.** The anthrones stimulate the colon as senna does, more harshly.

**Dose.** Cramps; chronic use depletes potassium.

**Standing.** Aloin was removed from over-the-counter laxatives in the United States in 2002 for want of safety data.

## What lore surrounds it?

An ancient tradition, recorded by later Arabic and classical geographers, holds that Aristotle advised Alexander the Great to settle Greek colonists on Socotra to secure its aloe trade: if true, one of the earliest instances of a ruler colonizing an island for a single medicinal crop. The tradition is widely repeated, but its ultimate ancient authority has not been pinned down.

## What did the older authorities say?

**Pliny.** Describes the aloe as like a squill but larger, with a root “like a stake driven into the ground,” a powerful smell and a bitter taste, the best imported from India; the Asiatic kind served only for its glutinous leaves laid fresh on wounds; wine-dealers, he complains, “use aloes for the purpose of heightening the flavour and improving the colour of their wines”; two drachmae of aloes are added to two oboli of scammony to temper its purging; and honey with aloes is given for bruises.

## Sources

- Dioscorides, *De materia medica*.
- “History of Socotra” (reference article).
- Pliny the Elder, *Natural History* 27.5, 14.8, 26.38, 21.44, trans. J. Bostock & H. T. Riley (1855), Perseus Digital Library.
- Guo, X., and Mei, N. (2016). “Aloe vera: a review of toxicity and adverse clinical effects.” *Journal of Environmental Science and Health C* 34.

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*Bitter aloes.* In *Materia Medica*, edited by B. C. P. Statema. Version 1, revised 2026-10-01. The Thinking Press. https://thethinkingpress.org/materia-medica/bitter-aloes

Historical description, not medical advice.