OK Kathleen - here's what I've got on blessed thistle:

Blessed thistle or Holy thistle ( Cnicus benedictus, Asteraceae or sunflower
family) is in the same family as milk thistle, chamomile, yarrow.  It is used
to flavour benedictine liquor and bitters.

Most likely pharmacologically active constituents:  cnicin, a sesquiterene
lactone, lignan lactones - both bitter.  Other constituents - terpenes,
fenchone,  citral, phenylpropanes ( and others considered less "active" but
including a couple alkaloids in small amounts).

Commission E monograph includes blessed thistle as efficaceous loss of
appetite and dyspepsia - dose: 4-6 g. dried herb or equivalent - notes action
from stimulation of salivary glands and gastric juices. In folk medicine, also
used as a cholagogue ( Bisset).  David Hoffman (New Holistic Herbal)
emphasizes it's use as a liver tonic and describes dose: 1 tsp.( 1 gram) dried
herb to 1 cup boiling water, infused 10-15 minutes, 3X/day, tincture  1-2 mls
3X/day).  None of these sources mention lactation.

Botanical Safety Handbook notes "High doses (more than "5 g/cup of tea/day)
may irritate stomach and cause vomiting." McGuffin et al also have caution for
use during pregnancy.

It can be considered to have some potential allergy or cross-sensitivity to
those allergic to ragweed.  Allergy potential due to cnicin which has been
associated with allergic skin reactions ( Commission E chemical glossary)

Rosemary Gladstar (Herbal Healing for Women) adds a differing female and
herbalist viewpoint - used with other "hormone regulators" for "menstrual
difficulties".  And, "Blessed thistle is most widely known for its ability to
stimulate blood flow to the mammary glands and thus increase and enrich the
flow of mother's milk."

Of course, there is as yet no human or even animal studies to provide evidence
for or against this statement.

Sheila Humphrey
BSc  RN  IBCLC
[log in to unmask]    Minnesota (not too far south of Lake Superior so Fall
colours at their peak)
++++++++++++++++++++++++++++++++
Strictly a side note on the issue of saggy breasts - Culpepper ( 1653 AD)
noted use of Lady's Mantle ( Alchemilla) for "flagging breasts" and Gladstar
notes it's current use as poultices in Switzerland to "tone and firm" breasts.