We recommend zinc all the time on this website. It calms down pimples like dropping an Arctic ice blanket on them, and deactivates the complex chemical reactions that lead to new pimples rearing their ugly head. Zinc achieves this by controlling your immune system and cutting off inflammatory responses…
…but which is the best form to take? That’s the question we’ll answer today.
There’s so many different types, at least 7 commonly sold ones on internet retailers, that you could be left with your head spinning.
It’s probably taken you years to realise that zinc is what you need, so the idea of the wrong protein molecule getting in your way at the last second is infuriating. You have enough to contend with, monitoring your face in the mirror, comparing the dosage to your dietary zinc intake, scouring nutrition tables to work out what your dietary intake is in the first place.
Therefore, to put this issue to bed and avoid more distractions, here’s the expert facts on the different zinc forms.
One – zinc oxide
Once the most common form of zinc in supplements, and also added to fertilisers and animal feeds. It’s an inorganic form of zinc, a white powder in its pure form. It’s biologically inert, and an ingredient of paints, glasses, and ceramics.
Uniquely compared to our other forms, zinc oxide is a cornerstone ingredient of sunscreens, one of only 17 sunscreen ingredients officially approved by the FDA. In fact, alongside titanium dioxide, it’s the only ingredient approved as ecologically sound by the trustworthy Environmental Working Group. Zinc oxide physically reflects UV rays due to its intense whiteness. It’s non irritating and deflects both UVA and UVB rays…
…but as a zinc supplement? Oxide is the single weakest form available.
Consider this classic study which fed it to 15 human volunteers without food. Compared to zinc gluconate and zinc citrate, zinc oxide was easily the weakest. Its absorption was just 49.9% compared to 60.3% for citrate and a near identical 59.9% for gluconate. That’s 10% of clear skin, heads-turning-on-the-street potential down the drain.
Similarly, this study gathered 66 pregnant women from Toronto, probably by standing on a street corner with binoculars. 18 women took zinc oxide while 19 took zinc sulphate, and sulphate. The results were clear cut, with no complications: zinc sulphate produced higher zinc levels in the blood. They concluded that “the form of Zn must be taken into account“.
The evidence is consistent that this basic form of the zinc mineral is the weakest. Dodge zinc oxide if you want to fulfill your clear skin fantasies (its sunscreen powers are another story though).
Two – zinc sulphate
Zinc sulfate is the most common form given to acne patients by dermatologists, when they’re not throwing antibiotics in your mouth.
This version is a simple combination of zinc with sulphur. It specialises in a different arena to sunscreen; zinc sulphate was registered as a herbicide back in 1973 and is world renowned for defeating moss (haunted mansion owners won’t be using it then). It’s also a popular brewing tool, a sort of secret weapon, because spiking it causes fermenting yeast to go out of control. You have to be careful to keep the quantities controlled or risk total yeast dominance.
As a supplement though, it commonly appears in fortified cereals. As an organic zinc, it is usually absorbed much more easily than zinc oxide, but it’s far from the best.
Two great studies summarise it well. Firstly, understand that the minerals zinc and iron compete with each other in the gut, for absorption through epithelial cells. Therefore, we have this experiment where zinc sulphate or zinc oxide were added to wheat balls, which were already supplemented with iron to feed starving rural populations. Only zinc sulphate decreased iron absorption into the bloodstream, clearly showing the competition and demonstrating that sulphate was working.
But this similar study punctured a hole in it, as oxide and sulphate were both added to maize tortillas, eaten alongside meals of beans and milk – a meal you might eat when taking your zinc supplement (after your caviar and dinner with the prime minister, obviously). The two were statistically equal, with oxide’s absorption (10.8%) edging out sulfate’s (10.0%).
But zinc sulphate was also dramatically superior in the first study of the zinc oxide section.
What really matters is acne. Great news – this fantastic zinc and acne study, where it reduced troublesome pimples by 33%, used zinc sulphate.
If your acne is caused by zinc deficiency, then zinc sulphate will almost certainly cure it. However, if you have problems which decrease zinc absorption like high copper intake, low protein intake, and eating too many phytates from wheat, then others are better. Such as…
Three – zinc glycinate
A simple combination of zinc with the amino acid glycine. This organic zinc form is used in a small minority of products, but after sifting through the evidence with a fine toothcomb, my verdict is that zinc glycinate is the best zinc supplement you could choose.
The hard scientific data spells it out well. Zinc sulphate is a decently reliable form which is already proven to clear acne. Nevertheless, zinc glycinate was 16% better absorbed in a study on 24 rats. 49% passed into the bloodstream versus 42% for sulphate.
Another excellent study tested 12 young adult women, giving them a single 4 hour dosage of zinc glycinate, zinc picolinate, zinc citrate or zinc oxide. Beneath the victor (which you might have guessed), the figures shuffled around. For erythrocyte zinc concentrations (red blood cells), it was picolinate > oxide > gluconate. For unbound bloodstream zinc, the lower hierarchy was gluconate > picolinate=oxide.
For both categories though, glycinate sat on the throne of zinc absorption.
This form will also give you a small bonus of the amino acid glycine, which is important for glutathione, but many people lack. It won’t compare to a scoop of flavourless gelatin, but still.
Why is zinc glycinate so well absorbed? Supposedly because glycinate is the smallest amino acid in the human diet, travelling through the intestinal wall more easily, and that it does not ionise easily. It’s still a mystery.
Zinc glycinate is also a prescription remedy for arthritis, combined with plant-derived bioflavonoids.
Four – zinc orotate
This is easily the most mysterious zinc form on the list. The clouds of hype swirling it are thick and impenetrable, but it has the least studies compared to its zinc brethren.
Zinc orotate is a combination with orotic acid, which was once part of the B-vitamin family, even called vitamin B13. Supposedly, orotic acid is neutrally charged, allowing the zinc it carries to slip through the gut’s semipermeable membrane more easily. So does the orotic acid’s tiny molecular size.
Orotic acid is produced naturally in the body, and supposedly this simplifies its transportation. These legends also apply to magnesium orotate and potassium orotate, also considered supreme supplemental forms.
Orotate has a deep backstory involving the German scientist Dr Hans Nieper. He developed the theory that orotate bound minerals do not dissociate, or split into the ions as they pass through cell membranes. They only release the ions when they bind with the receptors where they exert their health effects. He argued that orotic acid is part of the body’s natural mineral transportation system for electrolytes, meaning that supplementation mimics a perfectly natural process.
Nieper supposedly treated thousands of patients with his mineral transportation theories, including heart attack sufferers. He was dubbed a charlatan by some, and a revolutionary by others.
These theories could easily be true, but for some reason, only one study has been documented on zinc orotate. It’s also 38 years old, and makes less sense than a hall of mirrors sprayed with LSD gas.
In rats, zinc orotate was compared to zinc sulfate and the obscure zinc pantothenate. The latter two were equal in absorption efficiency. However, zinc orotate was absorbed much more slowly into the bloodstream, following oral consumption. Once inside, it was removed more rapidly, but also distributed around the body more effectively. Complicating things further, the study was on rabbits.
Zinc orotate might be the unstoppable zinc of internet legend, but the evidence is unsteady.
Five – zinc gluconate
A middleweight of the zinc world, never achieving giddy heights, but ploughing through the supplement market and always surviving.
It had a controversy where the FDA warned against zinc gluconate nasal sprays, designed for colds, saying that they could permanently ruin your sense of smell. But they specified that this didn’t apply to supplements, so how do they fare?
Firstly, there’s the zinc oxide study above where 60.9% was absorbed versus 49.9% in the feeble zinc oxide. The second study was a rematch, but with the same result. 12 men aged 21 to 31 took both for 14 days, and the bloodstream peaks in zinc were 8-18% higher when taking gluconate compared to oxide. The noble scientists concluded that “Zinc absorption in humans could be improved by zinc complexation with gluconate“.
It’s all decent, but what is zinc gluconate? It’s a combination of zinc with gluconic acid, a metabolite when microorganisms ferment glucose. Unfortunately, BLACK MOULD performs the fermentation, specifically aspergiullis niger. Corn dextrose is the material in this fermentation.
This is great for nutritional companies, as they can have vast legions of obedient mould stretching out before their towers, pumping out ingredients while they cackle madly, but aspergillus niger is the same mould that makes deadly mycotoxins in peanuts like aflatoxin B. There’s a controversy over citric acid made by the same moulds, and whether inflammatory proteins might be hidden inside.
Could gluconic acid have the same problem? It’s such a tiny proportion of the supplement that you’d think it’s safe, but there’s no reason to use this form anyway.
Six – zinc picolinate
This is commonly stated as THE best zinc form to take.
If you’re willing to cut no corners when it comes to casting out the common cold or deleting your pimples, then you take zinc picolinate. But is it overrated?
Firstly, this 1987 experiment might be the most referenced study on zinc forms. It was fantastic for picolinate, as zinc citrate, zinc gluconate and the placebo failed to achieve increases in 15 healthy men, in the measured areas of the hair, urine and red blood cells. Zinc picolinate, meanwhile, succeeded, although citrate and picolinate both increased zinc slightly in the bloodstream. It was a 4 week experiment, mimicking the length of your epic acne-clearing quest (although, lets be honest, this quest only involves popping a pill every night).
However, we also have the second glycinate study above, where picolinate was defeated by that glycinate for both bloodstream and red blood cell absorption. Furthermore, picolinate was beaten by gluconate for bloodstream zinc.
The fact that gluconate didn’t increase zinc at all in the first study hints at a possible flaw. So does the fact that the placebo increased bloodstream zinc while gluconate didn’t. The male volunteers might have coincidentally had high bloodstream zinc already, which could never be nudged up any further; there was only 15 of them, after all, a sample size which can easily be distorted.
Picolinate is a form attached to the amino acid picolinic acid. It’s a chelated zinc, biologically active. Picolinic acid is released naturally in the human body, during digestion, to promote transport of minerals and compounds. That’s a true fact, and it’s also the theory behind its greatness.
Nevertheless, I’m not convinced that the fantastic reputation of zinc picolinate is accurate.
Seven – zinc citrate
Zinc bound with citric acid. Made by pouring a bucket of metal into a carton of orange juice. OK, that attempt of mine last week to create a free supplement didn’t work (just joking), but zinc citrate is one of the more popular zinc supplements these days.
In chewable tablets, zinc citrate tastes much more pleasant than gluconate, acetate and sulfate, which have a metallic and bitter taste. For companies, it’s also dramatically cheaper than zinc gluconate at $30 dollars per kilogram of zinc versus $78.
It’s separate speciality isn’t sunlight defence or killing moss – it’s toothpaste. Zinc citrate deletes bacteria, and also pops up in mouthwash and chewing gum. In particular, bacteria in the mouth produce volatile sulphur compounds which zinc can counteract, making zinc citrate a bad breath buster.
Studywise, this 2014 one illustrated the situation well. Among 3 middling zinc forms, citrate was, you guessed it, the middling one. In rats, only zinc citrate and gluconate managed to accumulate in the prostate (fun fact – the place where zinc most heavily accumulates in the body) after oral consumption. However, only gluconic managed this at very lose doses. This was a 30 day long experiment. The conclusion ignored zinc citrate: “the use of zinc gluconate is worth considering as a possible means of zinc supplementation in men“.
But then there’s the first study of this article. Zinc gluconate achieved an absorption rate of 60.9%, oxide scraped to 49.9%, while with zinc citrate, 61.3% of this acne-clearing mineral was flowing into the participants’ bloodstreams, ready to do its deeds.
Like zinc sulphate, it’s not the ultimate zinc supplement, but it will get the acne-clearing job done – that’s the bottom line.
The only problem is the citric acid element again. These phantom mould proteins aren’t paranoid ranting, as scientists are even concerned.
Eight – zinc acetate
A combination of the zinc mineral with the acetic acid acid. Acetate has carved out its place in the zinc world as a common cold buster, typically sold in lozenge form.
A study found that sniffing, sneezing cold patients improved their recovery rate 3-fold by taking zinc acetate. Heavy industries use it to manufacture ethyl acetate, in wood preservation, and to make more zinc. It’s also a cure for Wilson’s disease, a genetic defect that causes copper to accumulate in the brain.
It’s a topical anti-itch ointment, but alongside zinc sulphate, zinc acetate is one of the common acne-clearing formulas. But is it even absorbed? Or is the zinc trapped behind an intestinal wall, dashing forward to clear your pimples for you, but unable to get through?
This study was very clear, with the only flaw being the small sample size of 5 men and 5 women. They each took zinc oxide and zinc acetate in a single 50mg dosage, a direct duel, a showdown for the ages with no weeks to prepare.
The area under the curve, the measurement of total zinc accumulation in the bloodstream, was 524mcg for zinc acetate at lower PHs and 378mcg at high PHs. Zinc oxide was defeated, with 364mcg absorbed at lower PHs.
What’s interesting was that at higher stomach PHs, zinc oxide’s absorption declined drastically. It reached only 66mg.
Zinc acetate fell too, but by smaller amounts. It’s known that acidity, like gastric juices, increase the bioavailability of zinc. That’s why eating zinc oxide with a meal typically increases its absorption. However, this study hints that zinc oxide is particularly affected by higher PHs. Maybe it’s the inorganic nature of this paint ingredient?
Regardless, zinc oxide should be avoided, and zinc acetate is a middle of the road zinc supplement.
The verdict!
The final point is the fantastic acne studies on zinc. Which forms did they use?
The 33% reduction study used zinc sulphate. However, an even better 49.8% reduction study used zinc gluconate. This study where 59.5% of patients improved by more than 50% used zinc sulphate.
Overall, zinc glycinate rules the roost in the zinc universe, without a doubt. Zinc oxide is bottom of the pile, without a doubt. Inbetween, things are more ambiguous, with various competing studies that only include a couple of forms, with various overlaps and murkiness.
The fact is that most zinc forms will work for acne – just look at those studies. The question is whether your absorption is secretly impaired and you need the best of the best.
Picolinate and orotate lack the studies, but they possess the logic. Zinc oxide should get back to painting walls.
Here’s my unofficial zinc form ranking: glycinate > picolinate > orotate > sulphate > acetate > gluconate > citrate > oxide.
Thanks for reading!