Liver chemistries usually improve within a few weeks of starting UDCA, and 90% of any benefit is observed after 6–9 months of therapy. Liver chemistries should be re-evaluated after 1 year of treatment. UDCA is usually continued lifelong. Up to 40% of people do not respond to treatment with UDCA. Patients with PBC who have an inadequate response to UDCA or those few (less than 3%) who are intolerant to UDCA are candidates for second-line therapies. Obeticholic acid (OCA) is FDA-approved for the treatment of PBC in individuals intolerant or unresponsive to UDCA. OCA is a farnesoid X receptor  agonist, and results in increased bile flow (choleresis). OCA is started at 5 mg daily, and liver chemistries should be rechecked after 3 months of treatment. If the liver chemistries remain elevated, then the dose of OCA may be increased to 10 mg per day. The most common side effect of OCA is pruritus. Fibric acid derivatives, or fibrates, are agonists of the peroxisome proliferator activator receptor (PPAR), a nuclear receptor involved in several metabolic pathways. While fibrates are approved for the treatment of hypertriglyceridemia, they exert anticholestatic effects and have been studied for the treatment of PBC. Among the fibrates, bezafibrate and fenofibrate, PPAR-alpha selective agonists, have been extensively studied as therapeutic agents because of their potential ability to decrease bile acid synthesis and bile acid-related hepatic inflammation. A randomized, controlled trial in 2018 showed its efficacy in patients with inadequate response to UDCA.
After the movies success Hughess team established a  chain of "Platinum Blonde clubs" in several cities and offered a $10,000 prize that would go to any hairdresser who could copy Harlows shade. Though Harlow denied her hair was bleached, the platinum blonde color was reportedly achieved with a weekly application of ammonia, Clorox bleach, and Lux soap flakes. This process weakened and damaged Harlows naturally ash-blonde hair.During the 1930s Lawrence M. Gelb advanced the formulas of the bleaching products. In 1950 Clairol, the company Gelb founded with wife Jane Clair, introduced the first one-step hair dye product that lightened hair, which became a huge success with the masses. Bleaching process
Using bleaching agents
Melanin pigments, which give hair a darker color, can be broken down with oxidation. Most commercial bleaching formulas contain hydrogen peroxide and persulfate salts, which under alkaline conditions created by ammonia or monoethanolamine can bleach the hair. Persulfate salts, in combination with hydrogen peroxide or alone, is known for its ability to degrade organics, after activation with heat, transition metals, ultraviolet light, or other means that produce the sulfate radical. Without activation, the persulfate anion is known to react with some organic chemicals, although with slow kinetics. When melanin is oxidized, oxygen gas is released. Products for bleaching ones hair at home usually contain a 6% solution of hydrogen peroxide, while products for use in a hair salon can contain up to 9%.