1.What Is D-Biotin?
Biotin (or vitamin B7, vitamin H) is one of the B vitamins. 
It is a water-soluble B vitamin which is also white to whitelike crystalline powder.
It is involved in a wide range of metabolic processes, both in humans and in other organisms, primarily related to the utilization of fats, carbohydrates, and amino acids.
It plays an important role in fat synthesis, gluconeogenesis, aspartic acid and other biochemical reaction pathways.
Biotin helps maintain many of your body's major systems. Like other B vitamins, biotin helps your body use enzymes and carry nutrients throughout the body.. 
2.How Chondroitin Works
Chondroitin helps link together sugar and protein molecules and serves an important role in maintaining the structural integrity of tissue. Its primary benefit and mechanism of action is stimulating regeneration of cartilage, which is the connective tissue that cushions the ends of bones within joints.
What do chondroitin supplements do? Chondroitin help build connective tissue throughout the body, including those that form joints and the gastrointestinal tract. Because it works by retaining water, chondroitin benefits include helping to add lubrication and flexibility to stiff or damaged tissues and joints.
3.Benefits and Uses
Improves hair health, including  shine, volume, and scalp coverage in women who experience thinning hair. 
Helps improve skin's hydration, smoothness, appearance and nails.
Relieves diabetes, hypertension and hyperlipidemia