The US government, however, thinks differently. Straightening treatments like the Brazilian Blowout are hugely popular in the States - and becoming more popular here too. But according to the US Department of Labor's Occupational Safety and Health Administration, some hair smoothing and straightening products - including the Brazilian Blowout brand - contain ingredients that could damage your health.
The ingredient they're most worried about is formaldehyde, which is used to bind keratin to hair, making it straight. But despite some straightening products being labelled as formaldehyde-free, the US government fund some contained dangerously high levels.
And exposure to such high levels of formaldehyde - as well as other potentially risky chemicals - could cause allergic reactions in salon workers as well as clients. According to the US officials, there have already been reported cases of problems including nosebleeds and eye irritation.
Over in California, meanwhile, the state attorney general's office has filed a lawsuit against Brazilian Blowout, as it claims the straightening solution contains approximately 8 that's considered to be a safe level.
Would you risk it for a super-straight do?