Paul Mitchell Tea Tree Scalp Care Regeniplex Tonic is a leave-on scalp spray from Paul Mitchell's Tea Tree Scalp Care line, made for scalps showing buildup or early hair thinning. Unlike a shampoo or mask, the 3.4 fl oz (100 mL) tonic is sprayed directly onto a clean scalp and left on rather than rinsed out, making it a daily leave-in step rather than an in-shower treatment.

The formula centers on Paul Mitchell's Regeniplex botanical blend - tea tree leaf water, Kakadu plum, red clover, turmeric, wild yam, ginseng and saw palmetto extracts - alongside biotin, niacin and panthenol. In an 8-week clinical study cited by Paul Mitchell, 85% of participants reported increased hair volume and strength. The product is labeled Color Safe, Paraben Free, and Made Without Gluten.

Because it's meant to be worked into the scalp rather than the hair lengths, it's designed to absorb without leaving hair greasy or weighed down. It's an ordinary at-home product - not a professional-only treatment requiring salon application - and can optionally be paired with the same line's Regeniplex shampoo and conditioner, though those aren't required to use the tonic.

Water, Alcohol Denat., Butylene Glycol, Ethoxydiglycol, Methyl Gluceth-20, Biotin, Niacin, Panthenol, Melaleuca Alternifolia (Tea Tree) Leaf Water, Pisum Sativum (Pea) Peptide, Terminalia Ferdinandiana (Kakadu Plum) Fruit Extract, Trifolium Pratense (Red Clover) Flower Extract, Curcuma Longa (Turmeric) Root Extract, Dioscorea Villosa (Wild Yam) Root Extract, Panax Ginseng Root Extract, Glycine Soja (Soybean) Seed Extract, Hydrolyzed Vegetable Protein PG-Propyl Silanetriol, Hydrolyzed Yeast Protein, Leuconostoc/Radish Root Ferment Filtrate, Saccharomyces Cerevisiae Extract, Saccharomyces Lysate Extract, Serenoa Serrulata (Saw Palmetto) Fruit Extract, Acetyl Tetrapeptide-3, Dextran, Glycerin, Tetrasodium EDTA, Phenoxyethanol, Polyquaternium-37, Potassium Sorbate, Sodium Benzoate, Fragrance, Citral, Citronellol, Coumarin, Eugenol, Geraniol, Limonene, Linalool