Topical minoxidil is an extremely popular medication for treating and preventing male and female pattern hair loss. With consistent twice-daily application, a majority of minoxidil users see lasting, positive results within a few months. But minoxidil has a few different mechanisms of action, and it’s not entirely clear to scientists what makes it so effective. Here are a few ways minoxidil might work to prevent hair loss and encourage regrowth.
It Addresses Follicle Miniaturization
In male and female pattern baldness, also known as androgenetic alopecia, a person’s hair follicles slowly begin to narrow. This narrowing, known as follicle miniaturization, is caused by genetics and hormones, among other factors. One of the main hormones associated with this type of hair loss is dihydrotestosterone, or DHT.
With time, the follicle shrinkage caused by DHT and other factors leads to thinner, weaker hair that breaks more easily. When the hair gets weak enough, it starts breaking or falling out before it’s long enough to be visible. Some follicles eventually stop producing hair, either permanently or temporarily. These are often called dead follicles, even if they are technically only resting.
At this point, balding starts to become noticeable to the naked eye. Depending on where dead follicles are located or how many an individual has, they’ll see thinning hair, balding, or a receding hairline. One way topical minoxidil works is by slowing, stopping, or reversing this process of follicle narrowing and hair breakage.
With regular minoxidil use, hair follicles may widen back to something approaching their original state. Scientists have a number of theories on what exactly causes narrowing to stop and follicles to rewiden. What’s important is, with minoxidil, the follicles may remain wide enough for hair to grow normally, without breakage.
It Gets More Blood Flowing to the Hair Follicles
Scientists think one of the reasons minoxidil works is that it prompts increased circulation and causes more blood flow to the hair follicles. More blood flow means more oxygen and nutrients that help the follicles stay healthy and produce hair. Increased blood flow may be responsible for stopping or reversing the follicle miniaturization discussed above. It may help prevent hair loss and encourage regrowth in other ways as well.
Minoxidil is what’s known as a vasodilator — a medicine that relaxes the blood vessels. As blood vessels relax, they likewise expand, in a process called dilation. Vasodilators like minoxidil are also prescribed (typically in oral form) as blood pressure medications. Vasodilators work by making it easier for blood to flow smoothly and efficiently throughout the body.
When the blood vessels are dilated, they can deliver more blood to hair follicles, which may help stop miniaturization. Increased blood flow can alter the hair growth cycle, too, meaning hair spends more time growing versus resting.
Specific nutrients in the blood that might make a difference in hair loss prevention include vitamins and minerals like biotin and iron. Scientists are also exploring the effects of proteins in the blood called “growth factors” that could prevent male and female pattern baldness. One of these growth factors, called VEGF, could be responsible for hair regrowth.
It Opens Potassium Channels
Some vasodilators work by assisting the movement of potassium ions through the cell walls. These are called potassium channel openers, and — like other vasodilators — they promote increased blood flow and reduce blood pressure. In turn, they enable more oxygen and vital nutrients to get to the hair follicles and encourage regrowth.
Potassium channel openers also cause certain types of smooth muscles, including vascular muscles, to relax. In this way, they allow the blood vessels to expand and deliver more oxygen and nutrients where needed in the body. As noted earlier, this increased circulation may work to enable stronger, healthier, thicker hair growth.
Potassium channel opening drugs are used to treat conditions like hypertension, asthma, angina, and certain other cardiovascular disorders. Minoxidil is likewise considered a potassium channel opener. In oral form, potassium channel openers aren’t an ideal first line of defense against conditions like hypertension because they cause too many side effects. But in the case of minoxidil, they’re effective and safe for topical use in preventing and treating hair loss.
Scientists have actually learned a lot about hair loss treatment from observing side effects in patients being treated for other conditions. Minoxidil, for instance, was first created to treat ulcers but was found to be ineffective. Over time, scientists and doctors observed its effectiveness at treating hypertension and, incidentally, encouraging hair regrowth.
Changes the Hair Growth Cycle
Minoxidil is also thought to work by shortening the resting phase of the hair growth cycle. During the resting — or “telogen” — phase, hair stops growing for roughly three months and just stays the same length. Minoxidil may shorten this period of hair hibernation and jump-start hair growth by stimulating the outer layer of the hair follicle.
Unfortunately, this jump-start can be a real scare for some minoxidil users. This is because when the resting phase goes faster, hair may suddenly start shedding (falling out) rapidly. When this happens, people panic, thinking minoxidil is making their baldness or hair loss exponentially worse. In actuality, this initial shedding is a sign that minoxidil is working, and new hair growth is coming soon.
Once the resting phase is over, the “anagen” (i.e., growing) phase of the hair cycle begins. Minoxidil doesn’t just make this phase come sooner; it might also make it last a bit longer. Typically, an anagen phase is around two to six years long. It’s not clear just how much minoxidil could prolong this timeline; researchers are still studying the possibilities.
In any case, the longer the growing phase lasts, the more hair follicle cells can grow and develop. In turn, this means hair can grow about half an inch every month. Longer growth phases mean longer, healthier hair — especially when follicles are wide and primed to produce optimal hair growth. In combination with the other effects of minoxidil, this lengthier growth phase means a better shot at a full head of luscious hair.
Good Results Require Consistent Use
Scientists still have a lot more to discover about exactly how minoxidil works to make hair regrow. But one thing is for certain — minoxidil works best if you remember to use it every day, at the right dosage for you. And it only keeps working as long as you continue using it, so don’t stop once you start seeing results.
