Allergies to sulfonamides, also known as sulfa drugs, are common. Sulfa drugs were the first successful treatment against bacterial infections in the 1930s.Theyâre still used in antibiotics and other medications, like diuretics and anticonvulsants, today.llergies to sulfonamides, also known as sulfa drugs, are common. Sulfa drugs were the first successful treatment against bacterial infections in the 1930s.
According to Madrasi.com, henna that is black is not henna---it is indigo. If you use it, your hair will turn black. However, because indigo is a natural colorant, it can be teamed with henna, but the powder will be red, not black.
Steps. 1. Preview the desired henna color on your hair. Do a strand test on a piece of your hair before trying to add henna to all of your hair. It is best to do this on a lock of hair saved from your last haircut or to snip off a piece (1 x 1 / 2.5cm x 2.5cm); otherwise choose a very inconspicuous part of your hair. If you're happy with the look, proceed to henna your gray hair. Ad. 2.