Beauty The Biotin Spray That 'Instantly Thickens' Thin Hair Is Packed With Dermatologist-Approved Ingredients It’s on sale for $19 at Amazon. By Eden Lichterman Eden Lichterman Instagram Twitter Eden Lichterman is an Amazon Ecommerce Writer for Meredith brands including InStyle and People. InStyle's editorial guidelines Published on March 19, 2021 @ 09:00PM Pin Share Tweet Email We independently evaluate all recommended products and services. If you click on links we provide, we may receive compensation. Learn more. Photo: Courtesy After a year of grief, loss, and sickness, we wouldn't be surprised if your hair is bearing the brunt of your stress. Whether your locks are looking thinner than usual or simply falling flat when you try to style them, a biotin-infused thinning hair treatment could be the answer. And thousands of Amazon shoppers recommend this biotin spray that they say "instantly thickens" their hair. The spray treatment is packed with nourishing ingredients, including biotin, protein, and caffeine. "Biotin is a B vitamin that supports enzymes that help with the breakdown of amino acids, fatty acids, and carbohydrates to help provide energy for your body," Dr. Michele Farber of Schwieger Dermatology Group told InStyle. She added that "biotin may help [with hair growth] if one is deficient in this vitamin." When asked whether a spray treatment can truly thicken hair in an instant, Dr. Farber said, "Certain ingredients in this spray, like protein, may be helpful for improving the appearance of hair by helping to mend the hair cuticle and reduce further damage." She also spoke about the benefits of caffeine for thinning hair, saying that caffeine may be "useful for stimulating hair growth and preventing loss in hormonally mediated hair loss [conditions]." All that to say that between the spray's three main ingredients — biotin, protein, and caffeine — you're likely to see volume right away and gradual hair growth over time. Courtesy Shop now: $19 (Originally $22); amazon.com The brand recommends using this spray on damp hair and then running over your locks with a blowdryer to reveal voluminous, texturized strands. You can use this product on all hair types, including color-treated hair. "Upon first use, this made my hair look thicker and fuller," one reviewer wrote. "I use it every time that I wash my hair now. Have gone through three bottles and will definitely continue to reorder." Another shopper added: "I'm not even through the whole bottle yet, and you can see a huge difference in my hair. This will make your hair grow longer and thicker fast! I use it every day, and I still have just under half the bottle. My hair has grown five inches in the last month." With dermatologist-approved ingredients and thousands of positive testimonials, we're confident this biotin hair thickening spray will give your hair the boost it needs after a difficult year.