Do Viral Beauty Hacks Actually Work? Checking the Chemistry
Every few months a new beauty hack makes the rounds: a condiment from the fridge doing the work of a salon treatment, a kitchen staple standing in for a $30 product. Some of these tricks have a real basis in chemistry. Others are just a coincidence dressed up as a discovery. Since so many of these hacks target hair color and texture, it's worth going through the actual chemistry of a few of the most persistent ones so you know what you're really getting into before you reach for the pantry instead of the product aisle.
The Ketchup-on-Hair Myth
The claim shows up constantly: coat your hair in ketchup, wait, rinse, and your color comes out warmer and shinier. The kernel of truth is that tomatoes are mildly acidic, and acidic rinses can have a very slight, very temporary effect on the outermost layer of the hair shaft, the cuticle. A mild acid can smooth the cuticle down so it lies flatter, which reflects more light and reads as extra shine. On very light, previously lightened hair, some people also report a subtle warming effect, similar to what a vinegar or lemon juice rinse can do.
What ketchup will not do is change your hair color in any meaningful, even, or reliable way. It is not a dye. It contains no pigment designed to bond with hair, and its acidity is diluted by sugar, salt, and thickeners that have nothing to do with hair chemistry. On dark or previously untreated hair, most people notice no visible effect at all beyond the smell and the mess. It is also worth remembering that whatever mild effect does happen washes out within a day or two, because nothing in ketchup is designed to bond permanently to the hair shaft the way an actual toner or color product is.
If you're chasing that "flatter cuticle, more shine" effect on purpose, a diluted rinse of plain white or apple cider vinegar in water does the same mild-acid job without the sugar, the smell, or the staining. Either way, treat it as a once-in-a-while shine trick, not a substitute for an actual toning product.
Mayonnaise as a "Deep Conditioner"
This one is more plausible than it sounds. Mayonnaise is mostly oil and egg, both of which are legitimate hair-conditioning ingredients in their own right — oils coat the hair shaft and reduce moisture loss, and the fat and protein in egg yolk can temporarily smooth the surface of the cuticle. Coating your hair in a thick, fatty substance for twenty or thirty minutes under a shower cap will genuinely make dry hair feel softer and look glossier afterward, in the same way a rich oil-based hair mask would.
The catch is that mayonnaise also contains vinegar, salt, and sometimes preservatives that have no business sitting on your scalp for half an hour, and the smell is exactly what you'd expect. A purpose-made deep conditioner or hair oil delivers the same fat-and-protein benefit in a formula that's actually designed to rinse out cleanly and smell like a hair product rather than a sandwich. If you want to try the kitchen version once out of curiosity, it isn't harmful for an occasional treatment — just don't expect it to outperform a real conditioning mask, and don't make it a weekly habit given the added ingredients that aren't meant for hair.
The Baking Soda "Clarifying" Rinse
A third hack that circulates constantly is using a baking soda paste as a DIY clarifying shampoo to strip product buildup. Baking soda is highly alkaline, and alkaline substances can lift the cuticle open, which does help dissolve oil and buildup — that part of the chemistry checks out. The problem is that a fully opened cuticle is also rougher, more porous, and more prone to tangling and frizz once it dries, and repeated use pushes hair further and further from its natural, slightly acidic resting state.
A gentler, more predictable option is a clarifying shampoo formulated with a balanced pH, or simply following up any harsh rinse with an acidic one (like the diluted vinegar rinse mentioned above) to help close the cuticle back down afterward. If you do try a baking soda rinse, treat it as an occasional reset rather than a regular part of your routine.
Why the Same Hack Works Differently for Different People
One reason these hacks generate such mixed reviews online is that hair doesn't respond to any of this uniformly, and porosity is the biggest reason why. Porosity is simply how easily your hair shaft lets moisture and other substances in and out. Low-porosity hair has a tighter, more compact cuticle, so it resists absorbing anything quickly — a quick ketchup rinse or a vinegar splash barely has time to do anything before it's rinsed away. High-porosity hair has a more open, gappy cuticle structure, so it absorbs (and loses) moisture and other substances much faster, which means the same fifteen-minute hack can have a noticeably stronger effect, for better or worse.
This is exactly the kind of variable the Hair Type Guide tool is built to sort out. Plugging in your curl pattern and porosity gives you a read on how your hair actually behaves, rather than relying on a hack that was designed around whoever posted the video's specific hair. If you're low porosity, you'll generally need more time, more warmth, or more repetition to get any real effect out of a rinse-based hack. If you're high porosity, the same treatment will act faster, but you're also more likely to overdo it and end up with drier, rougher-feeling strands, since porous hair loses moisture just as quickly as it takes it in.
A Simple Framework for Judging the Next Viral Hack
Before trying whatever hack shows up in your feed next, it helps to ask a few quick questions rather than taking it at face value:
- What is the actual ingredient doing? Is there a real property here — acidity, oil content, protein, alkalinity — that plausibly explains the claimed result, or is the explanation just "it worked for me"?
- Is the effect permanent or temporary? Most kitchen-ingredient hacks affect only the outer cuticle temporarily. If a claim promises a lasting color change or structural transformation from a condiment, be skeptical.
- What else is in the ingredient besides the "active" part? Ketchup isn't just acid, and mayonnaise isn't just oil and egg — read the full ingredient list of whatever you're considering putting on your hair for half an hour.
- Does my hair type make this more or less likely to work? Use what you know about your curl pattern and porosity (or check it with the Hair Type Guide) to set realistic expectations rather than assuming your results will match a stranger's.
Applying that framework, ketchup lands closest to "mostly placebo, mildly acidic, harmless novelty." Mayonnaise lands closest to "a genuinely functional but messier version of a product that already exists." Baking soda lands at "does something real, but the trade-off usually isn't worth it for regular use." None of them are dangerous to try once out of curiosity, and none of them are a substitute for products formulated specifically for hair.
The Bigger Picture
Viral beauty hacks tend to spread because they're cheap, novel, and easy to film, not because someone tested them against the alternative. That doesn't mean every hack is nonsense — several of the ones above do rest on real chemistry, just usually a weaker or messier version of what a dedicated product already does better. The most useful habit isn't refusing to ever try a kitchen hack; it's understanding what property of the ingredient is supposedly doing the work, matching that against what you know about your own hair's porosity and texture, and treating anything that promises a dramatic, permanent result from a condiment with a healthy dose of skepticism.