There are several supplements that are commonly used to promote relaxation, such as:

Melatonin: A hormone that regulates sleep and is often used as a sleep aid.

Valerian root: An herbal supplement commonly used to treat insomnia and anxiety.

L-theanine: An amino acid found in green tea that has been shown to promote relaxation and reduce stress.

Magnesium: A mineral that plays a role in muscle and nerve function and is commonly used to treat symptoms of anxiety and insomnia.

Passionflower: An herbal supplement that has been used to treat anxiety and insomnia.

Note: It's important to consult with a healthcare professional before starting any new supplement regimen, as some supplements may interact with medications or underlying health conditions.