On the website of British luxury beauty retailer Space NK, 'Wellness' is now a category in itself, alongside 'Bodycare' and 'Fragrance'.

Hong Kong is also on the trend: Joyce Beauty has begun stocking health supplements by popular high-end skincare brand Perricone MD. Products range from Alpha Lipoic Acid tablets (HK$270), which help combat signs of ageing by boosting cells' metabolic function, to Super Berry Powder with Acai (HK$530), a dietary supplement powder rich in antioxidants.

Most recently, Rodial has released its Crash Diet Kit (HK$920), which promises users a drop in dress size in 10 days if followed to the letter. Rodial founder Maria Halzistefanis says she wanted to create a step by step dietary regime that was easy to follow and extremely effective.

The kit comprises a two-week supply of Crash Diet Sticks (powder sachets mixed with water to flush toxins from the body), Crash Diet Smoothies (a low-calorie banana and strawberry flavoured meal replacement smoothie that gives 70 per cent of the recommended daily protein intake), and a Crash Diet Gel that claims to break down stubborn fatty cells and firm the skin.

'People are beginning to understand that good skin starts from the inside,' Halzistefanis says. 'My first range, Glamtox Sticks, are designed to give the skin a real radiance boost from the inside, along with an injection of collagen to erase lines and wrinkles. When the sticks launched, they sold out in minutes and our customers are always praising them for transforming their skin.'

However, the Crash Diet Kit has sparked controversy among beauty bloggers, one of whom wrote on Skin Deep (skindeepbeautyblogger. blogspot.com): 'We should be taking a responsible approach to healthy weight loss, not giving in to quick fixes and shallow promises.'

In response, Halzistefanis says that as long as the supplements are healthy and contain high levels of protein, they are safe. She says all supplements should be part of a healthy, high-protein diet.

Also hoping to capitalise on the trend is Functionalab, a premium brand of 'scientific' supplements. These products incorporate nutrition, pharmaceuticals and cosmetics by approaching beauty from the perspective of health.

Founder Francis Maheu says that rather than being a new trend, the concept of inner beauty is based on common sense.

'The convergence of health and beauty has been accelerating recently as scientists and consumers recognise the link between health, beauty and nutrition,' Maheu says.

'Oral dietary supplements with topical creams will have different and complementary effects. This two-pronged approach offers instant protection for the outer layer of the epidermis while beauty supplements nourish the skin with active ingredients at a deeper level to achieve long-lasting results.'

Functionalab's innovative branding, crossing over into the world of pharmaceuticals with its use of terms 'doses' and 'drops' and in clinical packaging, has wowed the industry.

The supplements include Beauty Doses (HK$350), capsules that cover a range of treatments; Liquid Doses (HK$180), a concentrated drinkable supplement; Health Drops (HK$275), water-soluble supplement drops, and Personalised Packs (HK$850-HK$950) of 30-day complete supplements.

Maheu says: 'Consumers are seeing the results and are changing their beauty routines to include supplements because they realise that health and beauty are inseparable.'

Hong Kong has no shortage of 'miracle' solutions for beauty and weight loss - just glance at the billboards in any MTR station. But will the city embrace this trend of treating beauty from the inside out?

Rodial, Functionalab and Perricone MD are available at Joyce Beauty.