A potion of youth? Quest for perfect complexion brings glut of facial serums.

Byline: Donna Kato

They call to us from gleaming counters with promises of dewy complexions and renewed radiance. Nearly every month, there seems to be a new collection of potions that claim to smooth away wrinkles, fade brown spots and bring back that elusive youthful glow. Try me before you go in for Botox or Restylane or a face-lift, they seem to say.

For those contemplating doctor-administered procedures, the cosmetic counter pitches seem convincing enough to give at least one or two of the creams a try. In fact, an increasing number of skin-care lines are created by practicing physicians.

We asked a dermatologist not affiliated with a beauty company to give us an honest assessment of the claims and ingredients, such as peptides and molecules, that entice some of us to spend hundreds of dollars each year on products touted as miracle workers.

Do they really work?

``I'm asked this question at least 10 times a day,'' says dermatologist Sunil Dhawan, a clinical assistant professor at Stanford University School of Medicine.

They work, the doctor says, but in a very limited capacity.

The reason: Most beauty products use a smaller concentration of the effective ingredients so that skin irritations are minimized.…