Castor Oil Packs for Cortisol and Stress: Separating the Trend From the Evidence

Castor oil packs, a cloth soaked in castor oil and pressed against the abdomen, often with a heating pad, for 30 to 60 minutes, have become one of the more visible wellness trends of the past couple of years. The pitch usually links two claims together: the pack "detoxes" the liver, and because the liver is supposedly involved in clearing excess cortisol, the ritual also helps lower stress hormones. It is a tidy chain of logic, but the two links do not hold up equally well under scrutiny.

Start with the detox claim, since it is the one most directly addressed by clinical experts. Specialists at the University of Texas MD Anderson Cancer Center have stated plainly that castor oil does not detoxify the liver, and that the body already has fully functional detoxification systems in the liver and kidneys that do not require outside help from a topical oil. No published clinical trials have shown that castor oil packs measurably change liver function markers like ALT, AST, or GGT, and there is no established biological mechanism by which oil applied to the skin's surface would reach and alter liver processing of cortisol or anything else.

That does not mean castor oil has zero documented biological activity, it just means the activity that has been studied is not about liver detox. Ricinoleic acid, the primary fatty acid in castor oil, has shown anti-inflammatory and pain-reducing effects in laboratory and animal research, including a study published in Mediators of Inflammation that found topical ricinoleic acid reduced swelling in an induced-inflammation mouse model. More recently, a small 2024 human trial published in the Journal of Cosmetic Dermatology, following 22 participants, found that a castor oil cream applied twice daily for two months modestly reduced under-eye pigmentation. That is a real, if preliminary, finding, but it is about topical skin pigmentation, not systemic cortisol levels.

On the specific question of cortisol, there is a notable gap: no published human studies were found directly measuring cortisol levels before and after castor oil pack use. That absence does not prove the practice has zero relaxation value, lying still with warmth on your abdomen for 30 to 60 minutes is the kind of quiet, low-stimulation break that plausibly supports a subjective sense of calm for many people, but that would be a rest-and-routine effect available from many similar rituals, not evidence that castor oil itself is doing something hormonally specific.

This is a useful case study in how a trend can bundle a testable claim with an untestable one. "Does this change liver enzyme markers" is answerable, and the answer from major cancer centers is no. "Does the ritual of a warm pack and 45 quiet minutes make someone feel calmer" is plausible but generic to relaxation itself, not specific to castor oil. Marketing tends to blur these into a single confident claim about "detoxing cortisol," when the honest picture is closer to: no evidence for the detox mechanism, some early evidence for topical anti-inflammatory skin effects, and no direct evidence either way on cortisol specifically.

What is proven: ricinoleic acid has documented anti-inflammatory properties in lab and animal studies, and a small human trial found a topical castor oil cream improved under-eye pigmentation. What is trend and marketing: the claim that castor oil packs detox the liver or directly lower cortisol, which lacks clinical support and, per MD Anderson, is not something oncology or hepatology specialists recommend as a detox strategy. If the pack is part of a calming wind-down routine, the relaxation may be doing more work than the oil.