One of my clients sent me an email with a link to a flyer from a supplement store where he had previously purchased protein powder with the question:  “Would you suggest any of these products?

My answer: “Nope. Actually the fish oil is good.

This was a timely question for two reasons:

  1. A friend had asked me the previous evening what my thoughts were on L-Carnitine, as she had bought some on sale at the same supplement store.
  2. I’ve been thinking about whether it’s appropriate for me, a personal trainer, to prescribe supplements to my clients. In fact I was thinking about the client who emailed me this question as there is a supplement I’d like to recommend for him (read on to see which one), but I worry that this is out of my scope of practice as a trainer to do so.

In answer to my friend’s question, I noted that I’d heard of L-Carnitine but I’m not knowledgeable about it. I suggested that she look it up on as they are a great source for impartial information about supplements (head here for my complete review of

Try them all?
Photo credit: Noodles and beef on Flickr

Here’s the rest of my response to the client:

“So here’s what I think about supplements:

  • Never make a decision about whether you should take a supplement based on a flyer. If you already know that you want to take a supplement, and you receive a flyer showing it is on-sale then great, but even then, make sure it is a brand that you trust.
  • If you’re going to take a supplement, you need to research it. And not just one source – find several. I strongly recommend you use as one of the sources, but not as the only source. Any time someone recommends a supplement to you, before you buy; read. This might seem like a lot of effort, but some perspective here: you’re potentially talking about taking a drug. A drug recommended by someone who is not a health care practitioner familiar with your medical history. Be aware and knowledgeable about it!
  • I’ll re-iterate that last point: If you don’t want to spend the time to read up about a supplement you’re contemplating, then you shouldn’t take the supplement.
  • I am honoured that you’re asking for my advice on this, but I’m a trainer; not a dietician; not a naturopath; and not a doctor. There are definitely some trainers who have a wealth of knowledge about supplements, their efficacy, side effects, and contraindications. But honestly even then, I don’t think your trainer should be your sole basis for whether to take a supplement. In my case, I read what I can, and ask questions of people I know to be experts when I‘m not sure, but I don’t think that makes me qualified to prescribe supplements beyond the few basics that essentially have zero side effects like fish oil, greens, and protein.
  • The guy who works at the supplement shop is also not qualified to prescribe supplements to you.
  • This is not to say that  you should not take supplements.  There are some effective ones, and there are some that may be great options for you. But if you’re going to take them, particularly with a goal toward fat loss, you really should do so with the input from a health care professional. Unfortunately we know that your doctor previously recommended Xenical, which is a fat blocker and thus a particularly poor choice for you when you were eating a low fat diet (based on your food journals). Given that, I think it’s fair to say you shouldn’t turn to him for input on supplements.
  • Lastly, don’t forget that supplements are just that – supplemental. The basis for fat loss still needs to be proper lifestyle habits including healthy eating, exercise, sleep, keeping stress at bay, spending time with people you love, and spending time doing things you love.

There is one supplement that I think might be a good option for you, but please, instead of taking my word for it, research it. It’s called berberine, a drug supplement that is “sometimes recommended for diabetes prevention and therapy”. My preference would be that, in addition to reading about it, that  you see a health care professional for advice on whether this, or any other supplement, is right for you. I know you have an appointment with your doctor soon, and hopefully he will actually do a full check to see if there is a medical reason that you’re having limited success with fat loss. Given that, I would suggest you not think about any new supplements until after that. If the outcome is that everything is fine medically, then I think the best next step for you will be to see a naturopathic doctor, who would be an appropriate person to recommend supplements.  I believe you would need to pay for that out of pocket (although check your insurance), but this is your health we’re talking about. I have two in particular that I can recommend.”


Elsbeth Vaino, B.Sc., CSCS, is a personal trainer in Ottawa, Canada. 


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  1. Thanks Erin. Wow, I am sooo slow at replying to comments! Gotta work on that.

  2. Wow Elsbeth,
    I couldn’t agree with you more. I believe that people only need some supplements because of their diet and lifestyle are so poorly managed, or because of illness and they should stick to safe and beneficial low dose of minerals and vitamins from a reputable chemist or health shop and see their naturopathic doctor.

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