I ended up on your blog while looking for information about agnus castus and PMS. A few months ago a counsellor asked me whether the episodes of anger or low self worth were happening at any particular time. For the first time in more than 10 years of counselling, therapy, CBT etc I realised that there might be a connection between me feeling like not me and PMS. I started looking into it and a set of completely new ideas opened in front of me. First, is the idea that the emotional pain I carry with me could actually be triggered from something different than my mind. Second is the idea that there are remedies. It is so great to receive an email like that, however, the writer of the email is finding it difficult to get the correct dosage of Agnus Castus and more importantly ascertain what the correct dosage is, as each supplier seems to calculate the active ingredients completely differently. Nature’s Best sell 100mg tablets, equivalent to 100omg of fruit, ratio 10:1 (this old stock*).
Prime Health, advertise (although you can’t actually purchase it) 20mg standardised extract tablets, equivalent to 24omg dried fruit, ration 12:1. This is the dosage described in the clinical data, and the only one I understand. Herbs sell Agnus Castus Tincture 1ml equivalent to 500mg, ratio 1:2 (again this is advertised as old stock.*) This is the response I received to information on dosage. “Our dose equivalence is 1ml (ie 10 drops) to 500mg of dried herb. So to get close to your current tablet equivalence you would take 0.4ml or 0.5ml (4 or 5 drops) three times a day.” (remember this is old stock, so you would have to take 5 times that, once new stock carries the THR logo.) *The reason these companies are pointing out they are selling old stock is because the new regulations of herbal medicines has restricted the amount of active ingredient per tablet/ ml. What that means is the recommended dosage is no longer based on data from clinical trials, but rather is based on the restrictions of selling herbal remedies under the Traditional Herbal Registration license (THR).
In short, up until 2011 herbal medicines were unlicensed (meaning dosage was not restricted). Since 2011 all suppliers of herbal remedies must apply for a license. In the case of Agnus Castus there are two sorts of licenses. The Traditional Herbal Registration (THR), which restricts dosage to 4mg per tablet, or the Marketing Authorization (MA), which would allow dosage of 20mg (based on Well Established Use). The information on dosage allowed under each type of license can be found in the EMA Community Monograph, which is the document to which member states should refer to when deciding on whether to an issue a license or not. Unfortunately, most high street and online stores have applied and been granted a Traditional Herbal Registration (THR), which means they can’t sell any Agnus Castus with a dosage higher than 4mg. So where you see the THR symbol on herbal remedies, it is a guarantee the dosage will be too low to have an effect. This means products from Boots, Kira and Holland & Barrett are not worth buying (unless you’re can afford and are prepared to take 5 tablets each day.)
They are selling 4mg tablets at the same price they used to sell 2omg tablets. Why has the EMA interfered? I hear you ask. It seems there is a grave fear in Europe that herbal medicines are dangerous and in particular they interact with prescribed drugs leading to undesirable effects. To protect the (silly) public all herbs must have a license in order to be sold. THR license is based on traditional use for thirty years, and doesn’t require rigorous clinical trials to be granted (even though there are rigorous clinical trials accepted by the EMA for Agnus Castus). Because of the lower requirements for THR, that means the dosage is set at a level where it is unlikely to have any effect (adverse of therapeutic). Which makes you wonder why Boots would bother selling the products at all (I have emailed Boots this very question and will post their response). They are in fact cheating their customers, by implying the drug will work at the lower dosage, despite overwhelming clinical evidence to the contrary.
So where can you get the correct dosage of Agnus Castus from? 1) Not from any supplier who has a THR license. If it’s got the THR logo, then it is going to be too low to be effective. You will need 5 times the dosage suggested. Products from Boots, Holland & Barrett, Healthspan, Kira all carry the THR logo. 2) Some companies are still selling old stock, this is likely to be at higher dosage. If it doesn’t have the THR logo it is likely to be old stock. Nature’s Best, mentioned above, wrote to me about their dosage, and the problems they are experiencing in restocking: “The Natures Best Vitex Agnus Castus currently provides 100mg of Vitex Agnus Castus fruit extract at a one a day dose. This is a 10:1 extract which means the starting material is 1000mg (dried fruit). Vitex contains the flavonoid casticin and we ensure that that our extract contains not less than 0.4% casticin per tablet which is an excellent marker of potency. At the time of formulating this herb we did review all of the data referring to tincture, traditional use and extracts that were available.
This was launched 14 years ago and we have received excellent feed-back from customer who have used it. In April 2011 the status of this herb changed from food supplement to medicine. We have applied for a medicinal licence but we are struggling to get the potency to match our current product. Nothing has been finalised yet and once we sell through our stock of food supplements, we will have to wait for our licensed product to become available. We are close (weeks away) from running out and although this may appear like a hard sell, I am really only telling you so you have the choice.” 3) If the product has a PL code (product license required for all medicines), which means the supplier has obtained Marketing Authorisation. Although I have not as yet found any supplier that has got an MA, I do have an email from one, who is attempting to get this (and will give you their details as soon as I can). I have also emailed the MRHA (UK regulatory body for medicines) to ask them if they have a list of suppliers who have applied for the Market Authorisation.
I await their reply. 4) Finding a supplier outside of the EU (possibly US or Canada). I wish the news was better, but the EU regulations have, in effect, decimated the herbal medicines industry, rendering the herbs ineffective, by restricting dosage to levels too low to be effective (this hasn’t just affected Agnus Castus). For more on the herbal industry’s take on the regulations, click here. Something is very wrong here. You have to wonder who really benefits from these regulations (the public or the drug companies), because as one herbal company, who emailed me this morning said: “The pharmacists at the MHRA will have their way with regard to recommended doses, their is nothing that can be done to prevent that. As you cannot patent a herb, it is highly unlikely a company would go to the expense of trials to justify market authorisation. So it is most likely once current stocks are are sold through and the MHRA has attacked the sale of agnus castus food supplements that agnus castus will only be sold at very low doses.”