PEN® eNews 15(1) January 2025 - All About Supplements

Dietary Supplements for Weight Loss

In general, nutraceuticals may have no effect or lead to clinically insignificant weight loss in adults.

Some nutraceuticals have been associated with both minor side-effects (e.g. gastrointestinal complaints) and major safety concerns (e.g. liver failure, organ transplant, death), while others have no reported adverse effects. Dietary supplement use should be individualized and discussed with the individual’s health care practitioner.

Common weight loss supplements that may be associated with liver injury include: GTE epigallocatechin-3-gallate (EGCG; a component of green tea extract); garcinia cambogia; caffeine supplements; yohimbine; Herbalife (saw palmetto and green tea extract); OxyELITE Pro (aegeline); Hydroxycut (ashwagandha, ephedra and green tea extract); and Slimquick (green tea extract and turmeric).

Grade of Evidence: A & B & C & D, depending on the supplement.

To see the full practice question, including the Evidence Statements, Remarks and References, click here.

Dietary Supplements for Attention Deficit Hyperactivity Disorder (ADHD)

Evidence is too sparse and biased to recommend that children and adolescents take herbal supplements or East Asian Herbal Medicine (EAHM) to manage attention deficit hyperactivity disorder (ADHD) symptoms. In addition, the long-term (>6 months) effects of these supplements in this population are unknown.

The effects of herbal supplements on ADHD symptoms in adults have rarely been studied. Saffron may improve the effect of methylphenidate when taken concurrently, while lobeline, cannabinoids and Pycnogenol may not improve ADHD symptoms compared to placebo. All successful studies were very short-term (<6 weeks) and the long-term effects of these products are not known.

Grade of Evidence: C 

To see the full practice question, including the Evidence Statements, Remarks and References, click here.

Melatonin for ADHD

Taking 3 to 6 mg immediate-release supplemental melatonin before bedtime probably improves total sleep time, sleep onset latency (i.e. amount of time spent trying to fall asleep) and sleep efficiency (i.e. time slept divided by time spent lying in bed), but probably does not affect ADHD symptoms, in children with attention deficit hyperactivity disorder (ADHD) and insomnia.

Taking 1 mg extended-release supplemental melatonin before bedtime may improve total sleep time but may not affect sleep onset latency, wake time after sleep onset and sleep efficiency in children with ADHD and insomnia.

Side-effects related to melatonin supplementation may be mild and have not led to discontinuation of the supplement.

Country-Specific Guidelines

The 2020 Canadian ADHD Resource Alliance (CADDRA) practice guidelines do not recommend melatonin as a first-line therapy for improving sleep in children with ADHD, but they recognize that a limited number of studies have shown that melatonin may improve sleep in this population. 

British and Australian guidelines for the management of ADHD in children do not mention melatonin.

To see the full practice question, including the Evidence Statements, Remarks and References, click here.

ADHD Content Has Been Updated!

Tools and Resources: Calculators and Professional Tools

Did You Know?

Not only can PEN tell you the latest evidence, but it can tell you what is different between current recommendations and the ones they replaced.

If you see the “updated” flag beside a Practice Question, hover your mouse over the flag. The reason for updating the content will appear. It might say “Reviewed and no new evidence identified that changes current recommendations ”, “New evidence added that supports current recommendations”, “New evidence added that resulted in change to recommendations” or “New evidence added that supports current practice recommendations and has resulted in a change in the grade of evidence”. See the image below for an example.

Happy reading!