[Lotus]

I was asked info on Vitex, here's some past and present, I hope it helps, apologies parts are complex.

Vitex works through the HPA (hypothalamus-pituitary axis). It (vitex) increases LH (luteinizing hormone) production while inhibiting the release of FSH (follicle stimulating hormone), leading to an indirect increase in progesterone and a normalization of prolactin levels.

effects of a special Agnus castus extract (BP1095E1) on prolactin secretion in healthy male subjects.
Merz PG1, Gorkow C, Schrödter A, Rietbrock S, Sieder C, Loew D, Dericks-Tan JS, Taubert HD.
Author information


Abstract
The effects of three doses of a special Agnus castus extract (BP1095E1)--extracts from 120 mg, 240 mg and 480 mg of drug per day--were examined within the framework of a placebo-controlled clinical study of tolerance and prolactin secretion in 20 healthy male subjects during a period of 14 days. There was good tolerance during the study as regards the following: adverse effects, the effects on blood pressure and heart rate, blood count, Quick's test, clinical chemistry as well as testosterone, FSH and LH values. During each study phase the 24-hour prolactin secretion profile was measured from the penultimate to the final day, and the amount of prolactin release was monitored an hour after TRH stimulation on the last day. A significant increase in the 24-hour profile was registered with the lowest dose in comparison to placebo, the opposite being the case with the higher doses, i.e. a slight reduction. In contrast to the administration of placebo, the 1-hour AUC after TRH stimulation resulted in a significant increase with the lowest dose and a significant reduction with the highest dose. The results suggest effects of the special Agnus castus extract which are dependent on the dose administered and the initial level of prolactin concentration

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In this study 20 patients out of 43 patients reported 37 adverse events (AE) on 20 mg dose

Efficacy of Vitex agnus castus L. extract Ze 440 in patients with pre-menstrual syndrome (PMS).
In conclusion, patients with PMS can be treated successfully with Vitex agnus-castus extract Ze 440, as indicated by clear improvement in the main effect parameter during treatment and the gradual return after cessation of treatment. The main response to treatment seems related to symptomatic relief rather than to the duration of the syndrome.
http://www.ncbi.nlm.nih.gov/pubmed/11129515

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40mg dose was well tolerated in this study of 207 participants that decreased from 26.17+/-4.79 to 9.92+/-9.01 for the treatment group:


treatment for premenstrual syndrome with Vitex agnus castus: A prospective, randomized, multi-center placebo controlled study in China.
CONCLUSION:
Vitex agnus castus (VAC BNO 1095 corresponding to 40mg herbal drug) is a safe, well tolerated and effective drug of the treatment for Chinese women with the moderate to severe PMS.
http://www.ncbi.nlm.nih.gov/pubmed?filters=&orig_db=PubMed&cmd=Search&term=63%2A%5Bvolume%5D%20AND%2099%5Bpage%5D%20AND%202009%5Bpdat%5D%20AND%20He%20Z%5Bauth%5D


This resouce (the best I've seen on VITEX) has 13 separate trail analysis:

Vitex agnus-castus Extracts for Female Reproductive Disorders: A Systematic Review of Clinical Trials
https://www.thieme-connect.com/products/...32-1327831


Finally:

At low dose (120mg per day) of chasteberry, prolactin production is stimulated, while at higher dose (240-480mg per day) prolactin production is decreased.
http://www.diagnose-me.com/treatment/vit...berry.html

So.... Bottom line, it looks as little as 20mg could work, though 40mg to 120mg makes better sense.