Quiz: Test Your Hair Straightening Smarts

The only way to straighten your hair without causing damage is by using special shampoos or styling products. These products may smooth frizz and soften curls, but they probably won't give you perfectly straight hair. Use moisturizing shampoos and conditioners labeled to fight frizziness. Straightening creams and serums applied before or after blow drying can also minimize curl by coating strands and adding weight to the hair.

Shampoos, styling products, and hot tools can give you smoother, straighter hair. But none lasts as long as chemical straightening. Chemical straightening breaks down the bonds in the hair, which give hair its texture, and then rebonds them. The result is straight, frizz-free hair that lasts anywhere from a few months to a year, depending on the process.

Some keratin straightening treatments have been found to contain unsafe levels of formaldehyde, a known carcinogen, or chemicals that release formaldehyde with heating. Side effects of formaldehyde exposure, especially for salon workers, include eye irritation, rash, headaches, breathing problems, nausea, and vomiting. When buying straightening products, read the label and avoid these ingredients: formaldehyde, formol, formalin, methanal, morbidic acid, formic aldehyde, methyl aldehyde, oxymethylene, glutaraldehyde, (glyoxal) ethanedial n-octyl aldehyde, aldehyde C-8, or caprylaldehyde.

Amino acid treatments are the next generation of hair smoothing treatments. The products contain no formaldehyde or aldehyde, so they may be safer than some of the other hair straightening options. Although the process may not give you pin-straight hair, it will give you smooth, frizz-free tresses for three to six months. The treatment takes two to three hours and must be done in a salon.

Anytime you put harsh chemicals on your hair and scalp, you risk damage. If they're not used right, chemical straighteners can cause scalp burns, breakage and, rarely, hair loss. The best way to avoid damage is by going to an experienced professional. If you plan to relax your hair at home, make sure to follow the directions carefully and never rush or skip steps.

No-lye relaxers aren’t as harsh as lye-based products, but they can burn your scalp and damage hair if you’re not careful. Here are some tips for using relaxers safely:

• Don’t scratch your head or brush your hair before applying relaxer.
• Do a test strand first.
• Don’t leave the relaxer on too long.
• Wash it out with a neutralizing shampoo, which removes traces of the relaxer.
• Get someone to help you.
• Protect your scalp by applying petroleum jelly before using relaxer.

Chemical straightening can cause serious damage if it’s not done by an experienced professional. Do your research and find a stylist who has plenty of experience with the type of treatment you’re interested in. Schedule a consultation in advance, so the stylist can look at your hair and make sure it’s compatible with the treatment. 

Straightening too often can damage hair. How often you’ll need to straighten depends on which treatment you use, so talk to your stylist. 

If you use a keratin straightener, you’re more likely to damage your hair if you do both at the same time. If you plan to color your hair, do it after you’ve straightened it. And try a semi-permanent dye rather than a permanent one.  Semi-permanent color is gentler on fragile hair.

However, it is safe to use an amino acid straightener and color your hair at the same time. 

A large round brush, preferably made of a ceramic material, is best for smoothing your hair with the least damage. Use a rolling motion of the brush while blow drying your hair. A boar-bristle brush uses your scalp’s own oils to smooth hair and tame frizz but won’t completely straighten your hair. Natural oils attach to the bristles and get distributed down the length of your hair as you brush, smoothing and protecting your tresses. 

Flat irons are the most effective way to straighten hair without chemicals, but they can damage your hair, too. To get good results and keep your hair healthy, pick a high-quality flat iron that has ceramic plates and adjustable heat settings. Start out on the lowest setting and adjust until it gives you the straightness you want. You can also protect your hair by using a silicone-based styling product before applying heat. Make sure your hair is completely dry before flat ironing.

A haircut is a quick and easy way to get rid of damage done by heat or overprocessing. But there are other ways to improve the look and feel of your hair. Shampoos and conditioners that are made for chemically treated hair can add moisture and make your hair look better. Products with dimethicone decrease static electricity and frizz and boost shine. Natural oils for the hair also help hair retain moisture and keep it straight longer.

Thermal reconditioning -- also known as Japanese hair straightening -- is the only straightening treatment that lasts until your hair grows out. It works best on medium-curly hair and takes anywhere from one to four hours, depending on the length and thickness of your hair. Your hair is soaked in a solution to break down its structure, then rinsed, dried, and flat ironed to the straightness you want. If you are planning to color your hair, you should wait at least three days after you've had it straightened to avoid damage.

A variety of chemicals are used to straighten hair, but it’s believed by the American College of Obstetricians and Gynecologists that only a small amount are absorbed into your body through your skin -- not enough to harm your baby. However, you may find that the fumes from the chemicals are hard to tolerate when you're pregnant. If you have concerns, ask your health care provider.