View Full Version : Evening primrose oil and herceptin

09-30-2009, 08:07 PM
Hello Tanya,

There is a thread on this forum that cites a scientific study supporting the use of evening primrose oil and herceptin, saying it is synergestic. It sounds like it got thumbs up and I'm wondering why oncs don't mention it?

I have only one herceptin left to do Oct. 8 and am wondering a few things:

How much evening primrose oil is recommended? Mg?

Is it recommended if one is ER- or weakly ER-?

Can one take evening primrose oil indefinitely?

I noticed it was an ingredient in the calcium/magnesium capsules I was taking, along with soy lecithin which I don't need - I assume?

I had thought evening primrose oil had some estrogenic activity - is that true? If so I don't need that!

Thank you,

10-02-2009, 10:00 AM
This is a very interesting study but I must caution that it is very early research. It is done on cell lines and has not been trialed in a clinical setting with actual patients. Nonetheless, it is intriguing. Evening primrose oil does have estrogenic activity and is not recommended in those with a history of hormonal cancers. I would caution its use until further research is performed. I am pasting the link to the study.


10-02-2009, 12:54 PM
Thank you Tanya. So little is known about herceptin interactions it seems.

Interesting study - glad I asked you about this. I will definitely steer away from this supplement.

As an aside - I was taking evening primrose oil along with other OTC's to help with my hot flashes in 2006-7, then got dx'd with breast cancer 2008. My doctor also had me on Estrace and vagifem before the breast ca dx. Being a DES daughter I think all that stuff really bumped my chances up for getting this disease.

Wish I knew then what I know now.

10-06-2009, 12:41 PM
Well it certainly seems like you are being diligent in self care. Congratulations on finishing your Herceptin this week too!

12-20-2009, 09:03 AM
My naturalpath strongly advised me to add Evening Primrose Oil to my list of supplements. Being her2+++, she felt that I will benefit from this supplement. I recalled reading this thread so I questioned if it will raise estrogen levels and my naturalpath replied with confidence that it will not.

My naturalpath specializes in women's health and has been treating breast cancer patients for over 2 decades. While doing a search this morning I came across another article that states that evening primrose does not raise estrogen levels. For those interested, I cut and pasted the link below.

Obviously there seems to be contradiction on this topic....


Safety of evening primrose oil for breast cancer patients
Affiliation: Abramson Cancer Center of the University of Pennsylvania
Last Modified: July 14, 2002

Dear OncoLink "Ask The Experts,"
I had stage I breast cancer last year. I am presently on tamoxifen, and of course I began hot flashes and night sweats. I am premenopausal. My surgeon recommended I take evening primrose oil for the hot flashes, which works great. However, I'm getting conflicted reports lately that primrose oil has estrogen in it. Knowing the tamoxifen blocks estrogen, I shouldn't' be taking something that is estrogen. Can you tell me whether I should be taking primrose oil?

Ellen Sweeney, RD, Clinical Nutrition Specialist Abramson Cancer Center of the University of Pennsylvania, responds:
Most herbals and supplements commonly used for relief of menopausal symptoms, or those symptoms commonly associated with tamoxifen use have been shown to have estrogen like properties (Dong Quai, Black Cohosh and soy). Evening primrose oil, however, has not been shown to have estrogen like effects. Its main compound that provides possible anti-inflammatory effect is gamma linolenic acids. Studies have shown evening primrose oil to be possibly effective in reducing mastalgia and PMS symptoms but effectiveness with relieving hot flashes has not been clearly shown. So, from an estrogen standpoint, it seems safe to take with Tamoxifen. Known drug interactions with evening primrose oil are anticoagulants, general anesthetics, and phenothiazines.

12-21-2009, 08:34 AM
Many commercial manufacturers combine evening primrose oil with phytoestrogens so be sure to read the label carefully.