Minoxidil is a treatment used widely by men and women with hair loss. The most common strengths are 2% and 5%. However, a 10% solution is also available, and some men use it to improve hair growth results.
This article will compare minoxidil 10% to minoxidil 5% and 2%. There are limited direct studies available on the topic, but the data that is available is pretty clear. We will also suggest some easy ways to improve minoxidil’s effectiveness, regardless of strength.
NOTE: Minoxidil 2% and 5% are the only solutions the FDA has approved for the treatment of hair loss in men. More studies are required on the benefits and dangers of minoxidil 10% as it is NOT an FDA-approved dosage. See a doctor before you proceed with treatment.
Minoxidil in the Treatment of Hair Loss
Scientists first developed minoxidil in the 1950s. Upjohn, the company that manufactured it, originally hoped to sell it for the treatment of ulcers but eventually marketed it as a vasodilator.
As studies continued, researchers found that minoxidil led to unexpected hair growth (1).
This was thought to be a result of its vasodilating properties, enabling the capillaries in the scalp to become dilated (2). This improves their ability to deliver nutrients and oxygen to the hair.
Over time, scientists performed further studies to better understand minoxidil’s role in the treatment of hair loss. This eventually led to the FDA approving it against male pattern baldness in 1988. It has been available ever since.
Is Minoxidil 5% or Minoxidil 2% More Effective?
Before we compare 5% to 10% minoxidil, let’s have a look at how the 5% strength compares to 2%. These strengths are both readily available and FDA-approved. For this reason, we have more data on this topic.
A 2002 study compared a 5% solution of minoxidil to a 2% solution in 393 men with Androgenetic Alopecia (AGA) (3).
Treatment lasted for 48 weeks. At the beginning of the study, 157 men were assigned to the 5% minoxidil group, 158 to the 2% minoxidil group, and 78 to the placebo group.
After the researchers had collected baseline data, treatment started. The researchers instructed patients to apply 1 mL of solution (either 5%, 2%, or placebo) to their scalp twice per day. The total daily dose was 2 ml.
After the initial visit (week 0), subjects returned every 4 weeks until week 32. They then returned every 8 weeks until the end of the 48-week trial. The researchers performed safety and effectiveness evaluations on multiple timepoints through the trial.
These were the results at week 48:
In all investigator results (nonvellus hair count, change in scalp coverage, and benefit from treatment), there was a significant advantage of 5% over 2% minoxidil. Men in the 5% group had an average of 18.6 new nonvellus (i.e. thick, fully developed) hairs in a small patch of the balding scalp. This compared to 12.7 for minoxidil and 3.9 for placebo.
Results at Various Time Points
Here is a look at the changes in the participants’ nonvellus hair counts over the course of the trial:
The 5% minoxidil solution performed better than the 2% solution at all times, beginning 8 weeks into treatment.
This study was not the only one of its kind. Another team of researchers performed a similar study in 2004, but this time they focused on female-pattern hair loss (3).
Again, the 5% minoxidil solution performed better than both the 2% solution and the placebo.
10% vs 5% Minoxidil
In 2021, we got the first study that directly compared the 5% to the 10% minoxidil strength (4). A research team out of Egypt recruited 90 men with all grades of hair loss. They treated them with either 5% minoxidil, 10% minoxidil, or a placebo. Treatment lasted 36 weeks.
The researchers assessed the treatment efficacy in various ways:
- Hair counts of selected small areas on the scalp in the frontal and crown area (macroscopic assessment).
- Dermatologists’ assessments of the before and after photos of the entire head (global assessment).
- Response to the pull test. This is a very simple test where the doctor gently pulls a strand of the patient’s hair. The test is positive if the doctor can pull many hairs and negative otherwise. It is a very quick and easy way to determine if there is excessive hair loss.
- The patients’ own satisfaction with the treatment.
As expected, both 5% and 10% minoxidil performed better than placebo. The surprise was in the difference between the 5% and 10% strengths. Contrary to the researchers’ expectations, the two strengths were essentially identical across all efficacy measures. If anything, the 5% strength fared slightly better:
- The macroscopic assessment showed that the 5% strength gave a higher number of new hairs in the vertex, and this difference was statistically significant. In the frontal area, the difference between the two strengths was minor and non-statistically significant.
- The dermatologists’ global assessments of the before and after photos found improvement for 88.8% of men in the 5% group. This compared to 87.5% for the 10% strength.
- The pull test also gave essentially identical results: 37% of men in the 5% group vs 37.5% in the 10% group changed from a positive test at baseline to a negative one at the end of the study. Such a change suggests the patient is no longer losing hair.
- 89% of men in the 5% group were satisfied with their results. This compared to 87.5% for the 10% group.
While the 10% strength was not quite as effective, it tended to produce more side effects. Here is how the side effects compared:
- Contact dermatitis (local skin irritation): 10% strength: 100% of participants – 5% strength: 22% of participants.
- Unwanted hair growth outside the scalp (hypertrichosis): 10% strength: 37% of participants – 5% strength: 22% of participants.
- Headache: 10% strength: 25% of participants – 5% strength: 11% of participants.
- Temporary hair shedding (“dread shed“): 10% strength: 100% of participants – 5% strength: 55% of participants.
The researchers concluded that there is very little if any benefit to the 10% solution. If anything, the 10% strength is likely to cause more side effects and lead to patients stopping treatment. They recommended that physicians only prescribe the 10% strength to selected patients who do not respond to the standard 5%.
Dose-Response – An Understanding of Drug Effectiveness
Dose-response is a common theme in scientific research. In simplest terms, it means that effectiveness increases as dosage increases, but only up to a certain point. After that point, further increases in dosage will produce no additional therapeutic benefit. They will only increase the side effects.
Comparing 2% to 5% minoxidil gave the first indication of this. Though the strength of the medication increased by 250%, the increase in hair counts was only around 46%. This means that we are already well into the area of diminishing returns, where ever-increasing dosages yield ever-decreasing benefits.
The effectiveness of minoxidil for most men probably levels off around the 5% strength. Any increase in strength after this will only produce more side effects. This was clear in the recent 2021 study that directly compared 5% vs 10%.
Side Effects: Minoxidil 10% vs. Minoxidil 5%
We saw how the 10% strength causes more side effects. Partly, this happens because, with the increased strength, more of the minoxidil is absorbed into the bloodstream. From there it circulates to the entire body. This can cause symptoms like headaches or unwanted hair growth in other parts of the body.
Remember that minoxidil is a potent vasodilator (5). When given orally it has the potential for serious side effects. For this reason, doctors generally only prescribe it for their hypertensive patients as a last resort.
Minoxidil at 2% and 5% are barely absorbed systemically. However, as the strength increases, it is inevitable that at some point some of the minoxidil will be absorbed into circulation. At this point, side effects become very common and more severe. This is one of the reasons that strengths higher than 5% are not FDA-approved and are relatively difficult to find.
If you want to use this 10% strength, you will only be able to do so through prescription. You will also need the oversight of a doctor for as long as you continue treatment.
What if Minoxidil 5% Is Not Providing Desired Results?
Statistically, even the 5% version of minoxidil will only work for around 1 out of every 2 men at best. The rest will see no results (6).
Rather than switching to the 10% strength, there are a couple of simple ways to improve the efficacy of the 5% solution.
The first is to start weekly microneedling sessions. Keep on applying the 5% minoxidil as normal for 6 days of the week. On the 7th day, skip the minoxidil and do a microneedling session instead.
Chemically Enhancing Minoxidil
Scientists now have strong evidence to suggest that the effectiveness of minoxidil can be enhanced if it is combined with other compounds.
One such compound is tretinoin. This is another medication normally used for acne and other skin conditions. Recent research has looked at the effects of adding tretinoin to a minoxidil solution. The results suggest this will stimulate regrowth for many men who would otherwise see no results from minoxidil (9).
Tretinoin-containing minoxidil formulations can be made through a compounding formulation or purchased online. In either case, you will require a doctor’s prescription.
Other FDA-Approved Treatments for Hair Loss
Finasteride is a 5-alpha-reductase inhibitor that decreases the levels of DHT in the body. This can be effective in stopping the progression of pattern hair loss, though it does come with potentially unpleasant side effects.
Men who switch from 2% to 5% minoxidil are increasing the potency of their medication more than two-fold. The result for most will be a mild increase in hair regrowth.
The available data suggests that any increase in strength beyond 5% will lead to negligible regrowth benefits. On the other hand, it will likely cause more frequent and more severe side effects. These will have a negative impact on patient compliance. The end result will be poorer regrowth.
For the vast majority of men with AGA, the 5% strength will be more than enough. Those who seek to boost their results further can combine minoxidil with other modalities.
Microneedling is arguably the best option. Another option is a minoxidil solution that also contains other active ingredients. Together, these ingredients can work to promote hair growth synergistically.