Botulinum toxin, a substance often referred to generically by its trade-named variant Botox, was originally developed to treat medical conditions such as muscle spasms and voice problems.

But its popularity soared following a chance discovery that it was incredibly effective in helping erase lines in the face. It works by temporarily freezing – or paralysing – a muscle, thereby softening lines and wrinkles while delaying the onset of future ones.

It soon became the go-to cosmetic treatment, particularly among celebrities: so much so that supplies were, at one stage, hard to come by at the height of its popularity in the mid-nineties.

Treatments are administered by small-volume and highly targeted injections. They are most effective when natural expression lines become visible – in the forehead, between the eyebrows, around the eyes and nose – something that tends to occur between the mid-20s and middle age.

Patients can typically expect to wait about a week to start noticing results from a treatment widely seen as among the safest of the non-surgical procedures.

And while it may be popular among A-listers for its anti-ageing powers, it has other uses: injections beneath the armpits can prevent sweating, or when targeted in the masseter muscles in the jaw, they can reduce tooth grinding and even used in the head to treat the effects of a migraine.

To be clear; Botox itself is a specific botulinum toxin type A product made by the drug manufacturer Allergan. It is only one of the brands used by Dr Joshua for toxin treatments. Others available in the clinic include the new long-acting toxin, which is effective for approximately six months.

Typical toxin treatments in which he specialises include wrinkle relaxation, jawline slimming, hyperhidrosis/excessive sweating, neck slimming/neck spasms and ‘lip-flips’.