Considerations if Choosing to Supplement with Piperlongumine 
Piperlongumine has the power to hinder specific enzymes in the liver and intestine responsible for breaking down various drugs and herbal compounds. This inhibition can lead to an increase in absorption and bioavailability of the substances. Piperlongumine strongly inhibits enzymes like CYP450 and UDP-glucuronosyltransferases (UGTs), which are crucial in breaking down and eliminating drugs and some natural anti-cancer compounds from the body. This inhibition can lead to increased natural compound and drug levels alongside prolonged effects and this is why it's important to speak to your doctor before adding Piperlongumine to a cancer stem cell targeted protocol.
It's main super power appears to be it's produce oxidative stress, especially in the new bio-available liposomal formula. It's important to avoid antioxidants that may interfere with the oxidative stress such NAC, Vit E, Glutathione, and Oral Vitamin C for about 5 days prior and after the kill phase. During the kill phase Artemisinin, high dose IV- Vitamin C,  Silver Hydrosol, DCA, Fenbendazole, Omega-3, and Retinoic Acid (Accutane) increase the generation of oxidative stress alongside the Piperlongumine.
There are other off-label drugs and supplements many cancer patients take daily that are simply neutral, meaning they should be fine during an oxidative stress-induced kill-phase. Some of the neutral items include Vitamin D + K2, TUDCA, Thiamin B1, Milk Thistle, Serrapeptase, Probiotics, PECTASOL Modified Citrus Pectin, PEA, Magnesium Threonate, Low Dose Naltrexone (LDN), Fulvic Acid, Feverfew, Digestive Enzymes, Cimitadine and Caprylic Acid.
Most integrative oncologists, naturopathic oncologists and GPs trained in the metabolic approach will advise their patients individually as to whether to continue or pause for 1-2 days prior and 1-2 days after a kill phase when patients are taking powerful anti-cancer compounds such as Liposomal Berberine, Curcumin, EGCG, Quercetin w Bromelian, Liposomal Honokiol, Liposomal Bacalein, Liposomal Betulinic Acid and Danshen (Salvia Miltiorrhiza).
Many critical factors need careful consideration on an individual basis when strongly up-regulating oxidative stress levels in the human body whilst simultaneously inhibiting enzymes that detox many of these drugs and compounds. Certain drugs' effects on an individual, as well as their vulnerability to toxins, can be predicted through the use of SNPs. Speak to your practitioner about ordering a SNP's test which will help you make informed choices regarding the introduction and frequency of prolonged oxidative stress phases within the broader game plan. Before jumping from one kill phase to another, a dead cell clean-up and recovery phase supports the heart, liver, kidneys and immune system. In his latest book, Cancer Unravelled, McKinney writes that the saponins in herbs such as astragalus and ginseng help fragment dead cancer cells into antigens that can be presented to dendritic and other immune cells." Clever little saponins working for us post-kill-phase. Pro-resolving mediators alongside Boswellia with high AKBA content may help lower inflammation whilst simultaneously inhibiting methionine which may keep glutathione levels a little lower and prime the cells for the next oxidative stress phase.

So just a recap. Piperlongumine increases ROS accumulation inside cancer cells and normal cells and turns off Glutathione's antioxidant-making capacity (in all cells). Like all strategies that increase ROS, we need to figure out our own sweet spot that balances the risk of damage to healthy cells and the degree of damage to cancer stem cells. We must always clean up our dead cells and give our organs and immune system time to recover after and between heavy hitting with prolonged and enhanced oxidative stress.

Sourcing Regular and Liposomal Piperlongumine 
Long pepper will increase the absorption and bioavailability of other substances and support the digestive and immune system. Even though it's not the strongest of the two options, remember to speak with your doctor, go carefully, and take notes about the other compounds and drugs you are taking simultaneously.
For Piperlongumine, a liposomal piperlongumine can be used in a pulse fashion either by itself or alongside a standard long pepper capsule during a cancer kill phase. A Pro Liposomal Piperlongumine formula has the capacity to enter the cells via liposomal delivery and, once inside, has the potential to inhibit a number of cancer stem cell pathways glycolysis, generate powerful ROS and inhibit glutathione as a part of a kill-phase.