Herbal highs

They may be legal but are they safe? Read on before you bulk-buy those 'heaven drops' from that festival stall.

Wormwood

The herb with a spicy, bitter taste that gives absinthe its unique kick. Contains thujones, chemicals that act on the same brain receptors as cannabis.
Highs: Narcotic-like effects, vivid dreams.
Lows: Wormwood contains a toxin that taken in high quantities can bring on tremors, convulsions, sleeplessness, miscarriage, paralysis, stomach problems, and brain damage.
The law: Absinthe was never formally banned in the UK, but was outlawed in many other countries.

Datura (AKA thorn apple, devil's apple, stinkweed)

The leaves and flowers of a plant that grows wild in India, Mexico and the United States. Active ingredients are hyoscine and atropine.
Highs: Euphoria, visual distortion, hallucinations and sleep. Intoxication can last from a few hours to many days. Hallucinogenic effects are only achieved at near-fatal dosage levels.
Lows: Prolonged use can severely damage the heart, and cause amnesia, confusion and sluggishness. Smoking datura can cause blacking out and severe headaches.
The law: Not controlled under the Misuse of Drugs Act but the Medicines Act states that possession is permitted for personal use only.

Guarana

A berry that grows in Venezuela and the north of Brazil. Contains guaranine, a substance similar to caffeine.
Highs: A mild stimulant that quickens responses and delays sleep.
Lows: Unsuitable for those with heart problems or high blood pressure, may cause 'jittery' feelings and irritability.
The law: Not controlled under the Misuse of Drugs Act. Widely available in health food shops.

Ayahuasca (AKA dead man's vine, yage)

A vine native to the Amazon basin. Active components are alkaloids.
Highs: Mental clouding, hallucinations with colourful visions.
Lows: Trembling and sweating shortly after taking this drug. Individual sensitivity is very variable, large doses may depress the central nervous system.
The law: Not controlled under the Misuse of Drugs Act. Widely available in health food shops.

Yohimbe

The bark and roots of a tree that grows in Cameroon, Gabon and Zaire.
Highs: Stimulant, mild hallucinogen, and also reputed to be an aphrodisiac by some users. Effects last from two to four hours.
Lows: Side effects include racing heart rate, irritability, headache, nausea, sweating, dizziness and frequent urination. May be dangerous if mixed with anti-depressants, sedatives, antihistamines, or amphetamines. Anyone with a heart condition, kidney disease, glaucoma or history of gastric or duodenal ulcers should avoid this herb.
Legal: Not controlled under the Misuse of Drugs Act but the Medicines Act states that possession is permitted for personal use only.

Salvia divinorum (AKA Mexican magic mint, holy sage)

A soft-leaved Mexican plant, containing psychoactive chemicals that have yet to be identified.
Highs: Strong effects can be difficult to attain from smoking dried leaf, but can cause short-lived colourful hallucinations, lasting up to two hours.
Lows: Some people also experience headaches and mild irritability following salvia use. May trigger latent psychological and mental problems.
The law: Not controlled under the Misuse of Drugs Act but the Medicines Act states that possession is permitted for personal use only.

Damiana

Leaves from a shrub found throughout Mexico, Central and South America and the West Indies.
Highs: Higher doses of damiana may induce a mild sense of euphoria, lasting around an hour. Some users claim it is an aphrodisiac.
Lows: Higher intakes may cause diarrhoea; harsh on lungs if smoked.
The law: Not controlled under the Misuse of Drugs Act but the Medicines Act states that possession is permitted for personal use only.