Here's How Long It Actually Takes For A Supplement To Kick In

How long does it take a supplement to start working?

This is one of the top searches on most health websites, which only makes sense as you purchased a supplement in hopes of feeling better and would like to know exactly when this "feeling better" business is going to begin.

However, this seemingly simple question has a fairly complex answer.

First and foremost, for our purposes here, let's define “working” as you feeling better, and the signs and symptoms you were feeling prior to supplementation begin to notably dissipate.

To back the boat up a bit, let's also focus on quality supplements that have research and quality control inspections to vouch for them (aka not encapsulated nonsense).

For example, you were tired, cold and cranky all the time, and your doctor diagnosed you as having iron deficiency anemia. You took a doctor-recommended iron supplement in addition to following a nutritionist's dietary recommendations.

Two to four weeks later, you noticed a bit more pep in your step, so what you're doing is beginning to work.

That example is laden with some pretty passive, suggestive hints on how to handle a deficiency:

- Noticing your signs and symptoms rather than continuing to ignore your own health and wellbeing.

- Researching said identified symptoms and then discussing with your health care provider rather than going down the WebMD rabbit hole of doom and gloom, only to come out with a self-diagnosis.

- Tests to confirm findings, at which time a supplement was recommended. In this case, a doctor recommended iron supplement that saved you great amounts of gastric woes. Doctors have the hookup to slow-release iron supplements that don't cause (or cause significantly less) nausea and constipation.

- You reached out to a nutrition professional for a nutrition deficiency.

- Following all that up with taking the supplements and eating well, making you an exemplary health student and all around awesome. Congrats on reaching one of the highest levels of adulting.

But back in the realm of reality, most of the time, we read an article or blog that mentions symptoms we're managing on the daily, and then we decide to take whatever supplement mentioned.

That can be fine, and in fact, if it's a credible source, this is actually how many start their journey toward health. It's called self-advocacy.

However, if the source is the supplement company itself, and/or you're reading the article in a moment of hypochondria, then there's a chance you've been had. Read the fine print, dear friend.

Here's how you can figure out how long it takes for a supplement to kick in:

Factor 1: Severity Of Deficiency

The biggest factor that dictates how long it takes before a supplement kicks in is how deficient you are to begin with.

Let's say nutrient stores are like pools. If your pool is empty, it's going to take longer to fill than if your pool is half or mostly full.

Factor 2: Supplement Dosage

The next factor is how much of the supplement you are taking. Going back to our pool, it's half full, but if you're only putting in a 5-gallon bucket each day, it's going to take a very long time to fill.

And that's not counting what the sun will evaporate, and if you get sick of the pool never filling and give up.

Conversely, if you break some laws to steal a firehose and hook that bad boy up to the hydrant out front of your house, you're probably going to cause some damage to yourself, the pool, a few lawn gnomes, the siding along the house and everything else insight. Plus, you'll have some reckoning to do with the law.

Taking megadosages of supplements is NEVER a good idea. You can reach toxic levels of even water-soluble supplements, and anyone trying to tell you otherwise could probable benefit from a course or to in molecular biology.

Factor 3: Absorption Rate

In a way, this goes along with factor two, supplement dosage, but it's also its own thing.

Dosage and absorption rate are basically sibling factors. The body can only absorb so much at a time. It's like how you can only drink so much water at a time.

Drinking 8 to 10 cups of water throughout the day is totally doable and makes you feel awesome. Drinking 8 to 10 cups of water all at once is a sure trip to Vomitville.

Going back to the iron deficiency example and mention of slow release iron supplements, iron is a metal, and asking your body to absorb metal — especially a lot at once — is a big request.

Sure, we need it to survive, but it's still a metal. Throwing a bunch in at once is going to make you feel sick because your cells are all like, “Dude! We only have so many receptor sites, and conversion from ferric to ferrous takes time! We cannot work under these conditions.”

This is why taking megadosages is a waste of time and money. It's also potentially very dangerous to you and aforementioned metaphorical lawn gnomes.

Show your cells some respect. It's like weight loss: It took time to gain all that weight, and it takes time to lose it. It took time for you to develop a deficiency. It's going to take time to amend that deficiency.

Factor 4: Supplement Quality

The quality of the supplement comes in next. In the US, there is no federal regulation on supplements, meaning purchases of vitamins, minerals and herbs are unregulated by the US government.

The FTC will come in and retroactively put the smackdown on supplement manufacturers that make fraudulent claims, cause people bodily harm or are found to major discrepancies between label and actual contents.

However, that means something bad has to happen first.

Supplementation inspection of quality is optional and at the company's expense. Reputable companies will pay that.

If you're trying to fill the pool with a hose that doesn't function, it's not going to fill.

Factor 5: Can't Do It Alone

All nutrients need other nutrients for their absorption and utilization. If you're supplementing with calcium, magnesium or zinc, yet deficient in Vitamin D, you're not absorbing those minerals.

If you're supplementing with iron, but deficiency in Vitamin A (beta-carotene), several B vitamins, Vitamin C or zinc, you're having issues ranging from absorption to utilization. To put this in terms we can all understand, what is Drake without Rhianna?

Factor 6: Cause Of Deficiency

What's causing the deficiency in the first place? How did your metaphorical pool become empty?

Is it a genetic situation? Is it a side effect of one of your medications? Do you need to make dietary changes? Have you been stressed AF and unaware that stress essentially drains your body of many nutrients, especially zinc?

If you don't resolve what's draining the pool, you may never top it off with water, let alone keep it topped off.

Factor 7: Food

Remember that supplement means “in addition to,” not “in place of”. The nutrients we need for health are the same ones we're intended to get from our food.

If you don't know how to do so, don't feel dumb. The majority of Americans aren't sure of this.

Speak with a nutrition professional to get legit advice on how to pair your supplemental efforts with a healthy, sustainable diet. While you get the hang of a new way of eating, you're taking your supplements in addition to what you're eating will help fill in the gaps.

What about those other kinds of supplements?

Americans spend billions annually on supplements. We really, really, really love supplements.

There are some good ones out there, and there is some pure, unadulterated crap out there. Herbal supplements are nature's medicine, and so it's a good idea to get a naturopath or other herbal health care practitioner involved before downing them.

Often, people will think because herbs are natural nothing can go wrong. Remember poison ivy, puffer fish, rattlesnakes and jerks are all-natural, too. That doesn't mean it's a good idea to put them in your mouth.

As for weight-loss supplements, stop. Throw away what you have, or take the manufacturer up on its money back guarantee.

When you get that refund check in the mail, set it on fire. It will yield the same results as taking the weight loss supplement with a less diarrhea.

If you feel the impulse to buy a weight-loss supplement, including a celebrity-endorsed skinny tea (crap your pants tea), follow the same procedure. Take money out of account, grab a lighter and set it ablaze.

Or, you could save your money and skip the fire hazard. You have options.

The Giant Answer

Quality supplements only work when you take them. How soon they work depends on many factors, and there is no magical moment when they kick in.

Eat your fruits and vegetables. Get some sleep. And keep putting in the work, work, work. Like Drake and Rhianna, eventually, it'll all come together.

This article was originally published on the author's personal blog.

Sheila Amir is the owner and writer of, where she inspires people to live happier, healthier, well-nourished lives. Sign up here to get great health, nutrition, wellness and food information delivered to you, along with some wit and random Stallone references.