Can you become addicted to lip balm? Does nail varnish really turn your nails yellow? Will an expensive conditioner work wonders on your hair?
In this extract from a new book, the top cosmetic scientists contributing to a popular website called beautybrains.com answer key questions about the everyday beauty products we use.
CAN YOU BECOME ADDICTED TO LIP BALM?
Yes. Skin is a complicated organ, with multiple layers. The top layer, the stratum corneum, consists mainly of dead, dried-up cells, and as those cells flake off they send a signal to a deeper layer of skin - the basal layer - to produce fresh skin cells.
Hooked: You can become addicted to lip balm as you can train your lips to rely on it to become moisturised
Hooked: You can become addicted to lip balm as you can train your lips to rely on it to become moisturised
This is the process of cellular turnover. When you apply lip balm regularly, you create a barrier that prevents the evaporation of moisture from the inner layers of skin. Since the top layer isn't drying as much as it would normally, the basal layer stops getting the signal to produce new cells and slows down production.
When you stop using lip balm, your lips dry out and your basal layer must start producing new cells again. But since your lips already feel dry, you apply more lip balm.

Once that application of lip balm has worn off and there are no new, plump, moist skin cells to replace the ones drying out, your lips feel dry again and you have to apply more lip balm. And so on, and so on. Use balm too often and you'll train your lips to rely on it.
WHY DOES NAIL VARNISH TURN NAILS YELLOW?

TIPS TO AVOID YELLOW NAILS

  • Wear a clear base coat under coloured polish to protect your nails from staining.
  • Choose a formaldehyde-free varnish.
  • Use a nail varnish remover with a whitening formula - most brands do them - or soak your fingertips in ½ cup of water and the juice of one lemon for up to 15 minutes, once a week, to remove stains.
  • Never try to scrape or file away stains: you'll damage and weaken the nail
Some of the darker-coloured polishes can stain nails because of a chemical reaction between the colorant and the nail plate.
This reaction is hard to predict because it doesn't happen to everyone or for every dark colour. It can also take a few days to a few weeks to occur.
Formaldehyde is one of the hardening ingredients used in some nail polishes. It can react with the keratin protein in nails to make them brittle and yellow.
DO LIP PLUMPERS WORK?
Yes - by irritating your lips and causing them to swell.
That tingly feeling when you apply them is not in your imagination; your lips are reacting to a menthol-type chemical called menthoxypropanediol used to stimulate the skin.
The plumping effect is only ever slight, and temporary. It's not a good idea to use them often because they might damage your lips.
IS IT WORTH BUYING EXPENSIVE CONDITIONER?
Will designer conditioners such as Philip B's White Truffle Conditioning Crème - which retails at an astonishing £65 (spacenk.co.uk) - make a difference?
Cheap conditioners, priced at less than £2, don't usually contain silicones, which are among the most effective smoothing agents. Once you get over that £2 barrier, the differences are less significant.
Buy what you like and can afford: Many expensive conditioners have the same ingredients as cheaper ones
Buy what you like and can afford: Many expensive conditioners have the same ingredients as cheaper ones
Pantene and TRES emme are among the best conditioners we tested and they're not expensive.
Even the high-end brands use the same basic ingredients as products costing £5 or less. As we always say, you should buy what you like and what you can afford.
DOES FACIAL CLEANSER NEED TO BE APPLIED WITH AN 'UPWARD MOTION'?

PAST-IT POTIONS
An estimated 50 million unused skincare products are gathering dust in UK bathrooms
We've all read the instruction on the packaging - 'apply cleanser in an upward motion' - but we aren't aware of any scientific need for this.
Our guess is that this is just marketing-speak.
Maybe the manufacturers think that since gravity drags your skin down, pushing your skin up will help get rid of wrinkles. It won't.
Extracted from Can You Get Hooked On Lip Balm? by Perry Romanowski, published by Harlequin Books S.A. © 2011 Perry Romanowski. You can order a copy via millsandboon.co.uk and other ebook retailers.