/www.wellnessresources.com/news/d-limonene-help-for-digestion-metabolism-detoxification-anxiety-breast-cancSafety and Absorption of D-Limonene :
["D-Limonene is rapidly and easily absorbed by the human digestive tract. The oil is spread throughout the body with a preference for fatty tissues such as white adipose tissue, breast tissue, the liver and brain. It exerts direct metabolic activity as well as combines with oxygen to produce a variety of secondary metabolites that are also biologically active.
An oral dose of 1.6 grams (1,600 mg) in humans was mostly cleared through the urine within 48 hours. A dose of 500 mg from specially prepared lemonade was cleared within 24 hours.
**The biological activity of a dose of d-Limonene lasts from 12 - 24 hours. A single dose of 20 grams of d-Limonene in healthy men was found to have no toxic effects. Ongoing supplementation with 100 mg per kilogram (about
7 grams per day for an average adult) was found to have no toxic effects.**
Doses up to 15 grams per day have been used in human breast cancer studies with no toxic effects. High doses of d-Limonene are considered safe for human consumption, with no toxicity to the liver or kidneys.
At these higher doses a person may experience belching of the oil, which is annoying but is not a health problem. Because the nutrient has relaxing and anti-anxiety properties, higher doses may make a person tired, (which may be quite useful as a sleep aid). Because the nutrient moves peristaltic motion forward, higher doses could cause diarrhea. Because the nutrient unclogs sludge in the gall bladder, higher doses could move stagnant bile rapidly into the digestive tract, which could cause nausea. Because d-Limonene has anti-fungal properties some individuals with an overgrowth of Candida albicans could experience a "die off" from a high dose (nausea or flu-like symptoms). These symptoms have been reported in human studies, in some people, when doses reach 7 - 15 grams per day. In other words, most uncomfortable symptoms with very high dose d-Limonene are not toxic symptoms but reflect a dose that is higher than can be easily metabolized based on a person’s existing metabolic situation. If any of these should occur when taking d-Limonene, cut back the dose or discontinue for a few days, then try a lower dose.
Useful metabolic doses of d-Limonene range from 1,000 mg to 6,000 mg per day (1 – 6 grams per day)."]
Most I ever took was 1000mg x 2 a day. Take when your relaxing as it can make orange burps for ten min or so if your moving around. When lyme was raging, I wanted to take more, but there is not much dependable info taking this with ABX.
Now I take only one every other night for maintenance / gut health. Feels like it last longer than 24 hrs.