“In humans receiving a dose of 2 g of curcumin alone, serum levels of curcumin were either undetectable or very low.
Concomitant administration of 20 mg of piperine with curcumin, however, produced much higher concentrations within 30 min to 1 h after drug treatment; piperine increased the bioavailability of curcumin by 2,000%.
Other promising approaches to increase the bioavailability of curcumin in humans include the use of nanoparticles (73), liposomes (77), phospholipid complexes (78), and structural analogues (75).
…As discussed in this review, curcumin has shown therapeutic potential against a number of human diseases.
Common to all of these studies have been the safety, tolerability, and non-toxicity of this polyphenol, even at doses up to 8 g per day.
The underlying mechanism for curcumin’s clinical efficacy seems to be modulation of numerous signaling molecules. However, because of the complex nature of the diseases, the underlying mechanism in many cases remains unclear.”
What about side-effects?
…“Although curcumin has been shown to exhibit beneficial activities in a plethora of human diseases with minimal toxicities, some investigators have reported undesired adverse effects associated with this polyphenol. Lao et al. (105) conducted a dose-escalation study to determine the maximum tolerable dose and safety of a single oral dose of curcumin in 34 healthy volunteers.
The volunteers were given escalating doses of curcumin ranging from 500 to 12,000 mg, and safety was assessed for 72 h after administration. Twenty-four participants completed the trial, seven of whom experienced minimal toxicity that did not appear to be dose-related. More specifically, these seven participants experienced diarrhea, headache, rash, and yellow stool. In another study, curcumin at doses ranging from 0.45 to 3.6 g/day for 1 to 4 months was associated with nausea and diarrhea and caused an increase in serum alkaline phosphatase and lactate dehydrogenase contents in human participants (14). In patients with high-risk or premalignant lesions, doses of curcumin above 8 g/day were unacceptable to patients because of the bulky volume of the tablets (28). In one study of patients with advanced pancreatic cancer, 5 of the 17 patients receiving curcumin (8 g/day) in combination with gemcitabine reported intractable abdominal pain after a few days to 2 weeks of curcumin intake (20).”
Read the study here: AAPS J. 2013 Jan; 15(1): 195–218.
So what is the take-away from above study?
Always take turmeric with black pepper (fat+heat increases bioavailability further, though we need more studies on this) or consider a liposomal form.
To be on the safe side, you never want to taker super dosages af anything without practitioner supervision, as liver-numbers need to be taken into account to ensure your liver is metabolizing whatever you are taking and not risk side-effects like mentioned above. This doesn’t mean we should be scared of herbal medicine, but it is MEDICINE, and especially when taking dosages that far exceed what we would get through food sources, it is key that we take it according to what else is going on in our body.
For more on rare side-effects on turmeric read the study here also:
Case Reports Hepatol. 2019; 2019: 6741213
As with anything the dosage makes the poison - let’s not forget we can get a lot of digestive side-effects should we choose to eat 50 pounds of carrots in one go. So no need to freak out here, but we do need to use our common sense and not think “the more the better” just cos something is natural.