For many of us, healthy, thick hair can be elusive. As we get older, hair growth tends to slow, and the remaining hair starts to thin out. Hair tends to dry out as we go about our busy days.

There are a variety of over the counter, as well as prescription, treatments to promote hair growth and retain current hair volume.

A few products that have caught my eye are hair oil and supplements. Folic acid, castor oil, and rosemary oil are just a few of the options readily available to treat your hair concerns.

Here’s a rundown of some treatments worth considering for better hair health.

First, what causes hair loss, thinning, and slow growth? The main culprit, besides aging, is stress! Yep, feelings of anxiety, anger, fatigue, and tension all rolled up into stress can affect your hair. So, instead of an oil to apply to your roots, why not try a calming essential oil to help combat all the symptoms of stress? There are aromatherapy oils like Goose Creek’s Unwind 100% Natural Essential oil in lavender and eucalyptus for your diffuser to help create a calm atmosphere. Over at Amazon, there is also Up Nature’s Calm Essential Oil Roll-On for more on-the-go stress relief. Roll this oil down the neck, behind the ears, and on the wrists, and breathe in calming scents.

Beyond stress, hair loss or thinning can also be a sign of a medical condition, such as alopecia. Weight loss, iron deficiency, polycystic ovary syndrome, and menopause are additional causes of thinner or patchy hair. It’s best to visit your doctor or a registered trichologist for tailored advice if you suspect you are suffering from a medical condition impacting your hair health.

If you are relatively healthy, have effective means of relieving stress, and are still looking for thicker hair, the newest hair craze to experiment with is rosemary oil. The idea behind this oil is that, by massaging into the scalp on a regular basis, rosemary oil helps fill out the hairline and encourages growth in sparse patches. Has this been proven by science? No. However, the very act of regularly massaging oil into the scalp can stimulate new hair cells. Also, massaging rosemary oil into your scalp for five minutes and leaving it on for a minimum of 15 minutes has antibacterial benefits for the scalp and hair. Plus, it can be very nourishing on dry hair.

You can use a once-a-week treatment like Pacifica’s Scalp Love serum in rosemary mint to soothe and hydrate your scalp to encourage hair growth. Or go with a rosemary-infused shampoo like Aveda’s Rosemary Mint purifying shampoo and work it into your follicles daily while you shower.

For many, it’s not so much that hair is actually thinning or growing slower, but the lack of hydration gives the appearance of stunted hair growth.

For a highly moisturizing treatment, consider castor oil, which is a vegetable oil derived from castor beans. For natural hair, which tends to be drier, check out Shea Moisture’s Jamaican Black Castor Oil Strengthen & Restore treatment mask. After shampooing, apply a generous amount from root to ends, place a plastic cap over your hair, and blast with a blow dryer at a low setting for about 15 minutes. Then let hair rest for half an hour and rinse thoroughly before styling as usual. For a less time-consuming treatment, check out Fable & Maine’s HoliRoots Hair Oil and apply it to dry hair, massaging into the scalp, then shampoo and rinse.

One ingredient that has been proven to help grow and restore hair is minoxidil. You can get this as a topical treatment like Rogaine or in a supplement form from brands like Nutrafol.

Other supplements to consider are those containing biotin, like Olly’s Heavenly Hair gummies or Nature’s Made folic acid tablets. Unlike oil, supplements work from the inside out to promote hair growth.

Lastly, there’s argan oil, which is effective at protecting hair from damage caused by pollution and UV rays. For daily use, you can opt for a leave-in conditioner product like Hask’s Argan Oil 5-in-1 Leave-In Spray over at Ulta. Or if your hair needs more moisture, try OGX Aragan Oil of Morrocco’s Penetrating Hair Oil Treatment that purports to penetrate the hair shaft while renewing and softening hair.

There is so much on the market touting hair growth and renewal. While some oils are more effective than others, the most important way to ensure hair health is by regular washing and hydrating. Massaging your scalp and protecting your hair from the elements takes it a step further and causes no harm. Just watch out for snake oil when shopping for hair oil.