A. There’s no hard and fast rule for that, due to all the physiological factors that can influence the rate at which melanin production diminishes. But if your hair seems to be graying rather rapidly, keep in mind the normal process of shedding. Most people lose approximately 50 to 100 strands of hair a day. The gray strands become more noticeable as the darker strands disappear. A condition called telogen effluvium, in which actively growing hairs suddenly enter telogen, or the resting phase, can speed up shedding to 300 hairs a day. This condition mainly affects women in their forties, fifties and sixties, as a response to physical or psychological stress. Major surgery, loss of a loved one, depression, or, yes, sudden shock, can start the process. So can a shortage of protein or iron in your diet. Your body shifts hairs into resting gear to conserve its nutritional balance. They fall out; you seem to gray faster.

A. Some women notice no difference at all between the gray hairs and the pigmented hairs on their head. Others will tell you they're coarser or frizzier. But, rest assured, even if the hair shows no textural changes, deep down inside, it has changed.

A gray hair has a different composition than a non-gray hair. Its cuticle is usually thicker. But it is missing its melanin, and some of its vital protein. You may think a shaft of gray or white hair is a stubborn, wiry little thing, but inside, it's a weakling. It isn't fortified by keratin, those vital protein bundles. In very dry hair, the keratin scales are totally lacking, with a greater potential for further damage.

Due to changes in the follicle, gray hair strands may eventually become thinner in diameter. Just the kind of hair that is less able to stand up to chemical treatments. If you regularly subject it to more than one process, say coloring and straightening, the cuticle can become damaged. Permanently. No product on the market can rebuild the cuticle, although they can provide moisture, and soften out the roughened edges on a temporary basis.

A. Without melanin, the hair isn't self-protected from the sun's rays. And so it tends to "weather," becoming rougher and drier. The overlapping cells of the cuticle (think roof tiles) normally protect the strand against water loss. But, when they weather, they don't lie flat like an armored shield, moisture is lost, and strands can be easily damaged by sun, heat, chemicals, or rough handling. They also don't reflect light as well. When cuticle scales are raised, light filters into the hair, rather than reflects off of it. This can account for a dull, lackluster appearance.

A. Half of all women will experience age-related thinning or loss after the age of 40. Because this shows up at about the same time many women go noticeably gray, it's perceived as part and parcel of the gray hair experience. It isn’t. If you want to know more about hair loss (and what to do about it), you’ll find this information in the book. In the meantime, check out Thinning Hair in the Care & Treatment section of this site.

A. You probably won't go bald because you keep plucking gray strands out. Left alone, a single hair has a "life cycle," of 4-5 years. After that, it falls out, and is eventually replaced with a new hair. But sometimes it’s gone for good. Some of the one hundred thousand hair follicles on your head, plus or minus, can simply stop producing new hairs. If it does return, it still won’t have its pigment, and you’ll pluck it out again. At some point, it may be one of those hairs that never return, but you didn’t cause it to go on permanent leave of absence.

A. Gray hair can tend to go off-color, as can pigmented or color-treated hair. A green or yellow cast is more noticeable, however, when no other "natural" color is present. But, surprisingly, it isn't as easy to influence the color as some people may think. There are really only four things that may change the color of your gray:

1. A product intended to color hair
2. High mineral content in the water environment
3. Sun exposure
4. Alkaline chemicals

A product such as a shampoo or conditioner with a tint to it will not deposit color on your hair. It’s not designed to do that. The color is simply to make it look appealing on the shelf. This kind of color does not stick to the hair. “Blue” shampoos, specifically formulated to brighten gray or silver hair will alter the color, but in a good way, offsetting traces of a yellowish cast. It’s not a permanent “fix,” however, and you shouldn’t use them every time you shampoo, as they tend to be drying. You can read more about this in the book, and find out more about the other causes of gray going “off-color” in the Care & Treatment section.