[Shakuhachi (OP)]

A lot of medicinally active compounds in herbs are non-polar.
An example are terpenes (myrcene, caryophyllene, linalool, limonene, pinene, ...), compounds which are virtually insoluble in water. (a polar solvent)

Tinctures use a mixture of water (H2O) and ethanol (C2H5OH) or water and glycerol to solute active compounds of herbs.
Ethanol has both polar as apolar properties - so does glycerol - so terpenes can be extracted pretty easily.

When I make an infusion of say lavender in water, the active compounds mostly should remain in the flowers as the solvent I'm using when making (herbal) tea is water of course?
(I don't drink oil infusions or something haha.)

In the case of lavender, the active compounds are found in the essential oil which primarily consists of the terpenes linalool and linalyl acetate.
But when I brew a cup of lavender tea I can still smell and taste the lavender in the infused water
and the infused leftover flowers are smelling less, which I would assume means a decent amount of the smelling compounds (which primarily are the terpenes) are taken out of the herb?

Can someone clarify this.
What makes herbal tea effective?

Thank you in advance

[SoniaS99]

A lot of medicinally active compounds in herbs are non-polar.
An example are terpenes (myrcene, caryophyllene, linalool, limonene, pinene, ...), compounds which are virtually insoluble in water. (a polar solvent)

Tinctures use a mixture of water (H2O) and ethanol (C2H5OH) or water and glycerol to solute active compounds of herbs.
Ethanol has both polar as apolar properties - so does glycerol - so terpenes can be extracted pretty easily.

When I make an infusion of say lavender in water, the active compounds mostly should remain in the flowers as the solvent I'm using when making (herbal) tea is water of course?
(I don't drink oil infusions or something haha.)

In the case of lavender, the active compounds are found in the essential oil which primarily consists of the terpenes linalool and linalyl acetate.
But when I brew a cup of lavender tea I can still smell and taste the lavender in the infused water
and the infused leftover flowers are smelling less, which I would assume means a decent amount of the smelling compounds (which primarily are the terpenes) are taken out of the herb?

Can someone clarify this.
What makes herbal tea effective?

Thank you in advance

That was great article on how lavender is used in herbal tea.Clove herbal tea is best for relieving you of any tooth pain.

[Bored chemist]

It is a good point.
Much of the oil should remain undissolved in the flowers.
However the amount you need to dissolve to get the scent of the material is tiny.
The high temperature also increases the solubility (and decreases the partition coefficient).

However, it's important to recognise that the smell of lavender is very nice, but it's not clear that it has much physical effect.
On the other hand, caffeine, for example, is quite soluble in water.