If your hair always seems greasy, even after washing it regularly, you're not alone. Greasy hair is a common issue influenced by factors like your scalp type, hormones, and genetics. Contrary to popular belief, it's not necessarily a hygiene issue but a result of how your scalp naturally produces oil. "Oil is essential for a healthy scalp," explains Aga Tompkins, a board-certified trichologist. To better understand the causes, treatments, and misconceptions around oily hair, I spoke with several trichologists and dermatologists. They also recommended products that can help manage oil without stripping your hair of its natural moisture. For those looking for a clarifying shampoo, NBC Selected reporter Zoe Malin recommends one she uses weekly to prevent her hair from feeling weighed down by other products. This shampoo is gentle, hydrating, and suitable for all hair types, thanks to its hydrolyzed keratin that reduces frizz and adds shine. Another favorite is a lightweight shampoo designed for fine hair and oily scalps. It uses coconut-based surfactants and rice protein to remove buildup, add volume, and hydrate the hair. For conditioner, a lightweight formula from Briogeo is ideal, especially for days when hair feels limp. It adds volume and reduces frizz without weighing hair down. A scalp scrub can also be an effective tool for managing oily hair. One product, which is used once a week in place of shampoo, exfoliates the scalp to remove buildup while keeping it healthy and clean. It's gentle enough to avoid over-drying and has a pleasant scent. For those on a budget, Dr. Hadley King, a board-certified dermatologist, recommends a shampoo containing salicylic acid and niacinamide, which helps exfoliate and support scalp health. For curly or textured hair, a clarifying shampoo with ingredients like apple cider vinegar and sea moss extract can help define curls and prevent breakage. Experts recommend considering ingredients like niacinamide, tea tree oil, and beta hydroxy acids when choosing products for oily hair. These help regulate oil production and gently exfoliate the scalp. Surfactants like sulfates can be effective for removing oil but may strip natural oils, so they should be used in moderation. It's also important to use a lightweight conditioner and apply it only to the ends of your hair to avoid weighing it down. Using a clarifying shampoo once a week and a dry shampoo in between washes can help extend the time between washes. The primary cause of greasy hair is overactive sebaceous glands that produce excess oil, or sebum, to protect the hair and skin. This can be influenced by genetics, hormonal fluctuations, stress, and lifestyle habits. Fine hair tends to show oil more quickly due to less surface area to absorb it. Over-washing with harsh products can make the problem worse by stripping the scalp of natural oils, prompting it to produce more. To treat and prevent greasy hair, focus on gentle products that remove buildup without over-cleansing. Avoid heavy conditioners and styling products that can weigh hair down. A weekly clarifying shampoo can help remove buildup, and maintaining a healthy diet and managing stress are also important factors. There's no one-size-fits-all schedule for washing hair, as it depends on individual scalp types, lifestyle, and products used. Some people may need to wash daily, while others can go every other day. However, skipping washes rarely fixes oiliness and can make it worse. For both men and women, the root cause of greasy hair is similar, though hormones can influence oil production differently. If greasy hair is accompanied by other symptoms like itching, redness, or hair shedding, it may indicate an underlying condition that requires a professional evaluation.