Anna Friel drinks tea made from curry leaves.

The 36-year-old actress - who has seven-year-old daughter Gracie from her relationship with David Thewlis - ''felt sick'' after finding grey hairs, so researched natural methods for preserving her brunette locks and discovered the unusual brew.

The 'Look of Love' star - who is dating Rhys Ifans - explained: ''I felt sick recently because I found one or two grey hairs and I read that curry leaves help to maintain your hair colour, so I mix them with hot water and drink it as a tea.''

Friel also drinks around 12 cups a day of the 'Master Cleanse' - hot cayenne pepper, maple syrup and lemon juice - as a detox and anti-ageing treatment and she's thrilled with the results.

She said: ''It's amazing. I've been drinking it for two months and I feel so much better and my skin has really benefited.

''I'm always searching for pure, natural skin products.''

To preserve her youthful looks, Friel also has regular ''vampire facials'' - which involves having her own blood re-injected back into her face.

In an interview in Britain's Grazia magazine, she said: ''If you're vain, as you get older you start thinking, 'I've got to do everything I can to save my skin.'

''Vampire facials involve taking two vials of blood from your arm and injecting it back into your skin.

''It's meant to help your skin heal itself and boosts collagen. It makes my skin really glowy and tight again.''