Maca extract supplement benefit, dosage, and side effects, review of safety, risk, and danger
Maca herb use as sexual enhancer, libido booster, and as a treatment for erectile dysfunction or impotence

Maca is a plant native to the Peruvian highland that started gaining popularity in the US in early 2000s. This herb is best known for its potential in improving energy levels, vitality, and sexual health. This herb is found in a number of herbal aphrodisiac formulas, including a popular and effective product developed by a medical doctor, Passion Rx. It is also added to some foods, nutrition bars, drinks, and even chocolate.

Botanical name
Lepidium meyenii is a cultivated root belonging to the brassica family used in the Andean region in South America, particularly in Peru and Bolivia.

Nutritional value
Dried maca root has about 60% carbohydrates, 10% protein, 8% dietary fiber, and 2% fats. Maca contains minerals, especially selenium, calcium, magnesium, and iron, and includes fatty acids including linolenic acid, palmitic acid, and oleic acids.

What substances are in this herb?
This root has quite a number of substances including uridine, malic acid, glucosinolates, glucotropaeolin and m-methoxyglucotropaeolin. Maca root also methyl-1,2,3,4-tetrahydro-beta-carboline-3-carboxylic acid (MTCA) which has an effect on the central nervous system.

Proper dosage
The dosage of maca can range from 500 mg to 2,000 mg a day. However, for long term use, we suggest a dosage of maca not to exceed 500 mg a day. As with most herbs or dietary supplements, it is a good idea to take a week off each month.

Maca extract supplement products you will find in health food stores or online
This herb is available in plain powder in a capsule and it is also sold as an extract with various potencies. For instance, you can find maca 2 to 1 extract which means it is about twice as potent as the regular powder. Many supplements have a 4 to 1 extract or higher. You may prefer the simple maca powder or you may try a maca extract product and find it more helpful to you. It is difficult to predict which form of this herb will suit your needs unless you try it.

Capsules
Maca (Lepidium meyenii root) 500 mg by Advance Physician Formulas nutritional company.
Maca root 525 mg
Root Extract 500 mg, 4 to 1
Root Extract (Lepidium meyenii) Standardized to 0.6% macamides and macaenes 300 mg with Maca Root Extract 4:1 25 mg

Powder
Maca Power, Raw Powder, 16 oz

Onset of action
Although some people may notice the enhancement within a day or two, it usually takes several days or up to a week or two for the benefits to be noticed. It also depends on the dosage, higher amounts would provide a quicker onset. Maca is not as potent an aphrodisiac as mucuna pruriens, tribulus terrestris, and tongkat ali which work quicker.

Side effects, safety issues, toxicity
No significant maca side effects have been reported. A review of published studies do not indicate serious safety issues or toxicity. However, as with most supplements, is is advised to not take this herb daily for weeks or months unless you take a break a day or two a week and a few days each month.

Benefits
It appears that this herb can be helpful in those who wish to improve their energy level and those who would like a natural herb that enhances sexuality.

Sexual health
There are many herbs that have aphrodisiac properties, some strong, others weak. We would categorize maca as a mild to moderate aphrodisiac. There have been some studies in humans with the use of maca extract as a natural method of sexual enhancement, as a treatment for impotence, and to reverse SSRI induce sexual dysfunction. Maca appears to have some benefit.

ED in men
Subjective effects of Lepidium meyenii extract on well-being and sexual performances in patients with mild erectile dysfunction: a randomised, double-blind clinical trial.
Andrologia. 2009. Department of Urology, Morgagni-Pierantoni Hospital, Forlì, Italy.
We carried out a double-blind clinical trial on 50 Caucasian men affected by mild erectile dysfunction (ED), randomised to treatment with maca dry extract, 2400 mg, or placebo. The treatment effect on erectile dysfunction and subjective well-being was tested administrating before and after 12 weeks the International Index of Erectile Function (IIEF-5) and the Satisfaction Profile (SAT-P). After 12 weeks of treatment, both Maca- and placebo-treated patients experienced a significant increase in IIEF-5 score. However, patients taking Maca herb experienced a more significant increase than those taking placebo. Both Maca and placebo-treated subjects experienced a significant improvement in psychological performance-related SAT-P score, but the Maca group higher than that of placebo group. However, only Maca treated patients experienced a significant improvement in physical and social performance score. In conclusion, our data support a small but significant effect of maca supplementation on subjective perception of general and sexual well-being in adult patients with mild erectile dysfunction.

For sexual dysfunction due to SSRI drugs such as Prozac, Paxil, and Zoloft
A double-blind, randomized, pilot dose-finding study of maca root for the management of SSRI-induced sexual dysfunction.
CNS Neurosci Ther. 2008. Depression Clinical and Research Program, Department of Psychiatry, Massachusetts General Hospital, Boston, MA, USA.
We conducted a double-blind, randomized, parallel group dose-finding pilot study comparing a low-dose (1.5 g/day) to a high-dose (3.0 g/day) maca regimen in 20 remitted depressed outpatients with SSRI-induced sexual dysfunction. The Arizona Sexual Experience Scale and the Massachusetts General Hospital Sexual Function Questionnaire were used to measure sexual dysfunction. Ten subjects completed the study, and 16 subjects (9 on 3.0 g/day; 7 on 1.5 g/day) were eligible for intent-to-treat (ITT) analyses on the basis of having had at least one postbaseline visit. ITT subjects on 3.0 g/day maca had a significant improvement in Arizona Sexual Experience Scale and in Massachusetts General Hospital Sexual Function Questionnaire scores, but subjects on 1.5 g/day maca did not. Libido improved significantly for the ITT and completer groups based on Arizona Sexual Experience Scale item #1, but not by dosing groups. Maca was well tolerated. Maca root may alleviate SSRI-induced sexual dysfunction, and there may be a dose-related effect. Maca may also have a beneficial effect on libido.

Blood pressure
Can maca supplement really lower hypertension. I had triple heart bypass surgery in 2010.  My doctors said that I should not take any supplement with the potential to raise my blood pressure which then was 182/123. After the bypass surgery, it is 160/110 in the mornings. After taking my medicines it lowers to 130/95, with the medication clondine it lower even more. My main question is “Can the maca supplement caused artery blockages or speed up the process of artery blockages”?  I used it last year, it improved my immune system. When my household had the flu I was never sick. Not to mention, it increased my sex drive tremendously, lowered my cholesterol.  But I was not taking my insulin as prescribed so the doctors said that this may have lead to the thick blood in my arteries too. Little confused about the whole issue and I would like to see if you can give me some clarity to the subject. I am switching between so many pharmacy medicines and I am really tired of it all.
   We are not aware of long term human studies regarding its influence on blood pressure. Much could depend on dosage and extract potency, along with interactions with medications, so makes it even more difficult to know when other meds are used together. No easy answers are available.

Effect on memory
Aqueous Extract of Black Maca (Lepidium meyenii) on Memory Impairment Induced by Ovariectomy in Mice.
Evid Based Complement Alternat Med. 2008. Research Center for Pharmacology & Toxicology, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing. China.
The present study aims to test two different doses of aqueous extract of black maca on learning and memory in ovariectomized mice. Black maca improved experimental memory impairment induced by ovariectomy, due in part, by its antioxidant and achetylcholine inhibitory activities.

Ovarian function
Is there any link between maca herbal use and ovarian cysts or ovarian cancer?
     A search on Medline in April 2009 did not reveal any studies when using the keywords maca and ovary or ovarian. Maca is not known to have a significant effect on hormone levels, however, the benefits and adverse effects of long term use are not known and it is not clear whether this herb has any influence, direct or indirect, on ovarian function.

Interaction with other herbs used for sexuality improvement
Maca, in low dosages, can be combined with other herbs used for libido improvement including eurycoma, epimedium herb, tribulus, mucuna pruriens, and others.

Review article
Lepidium meyenii: a plant from the highlands of Peru--from tradition to science.
Forsch Komplementmed. 2009; Gonzales GF, Gonzales C. Instituto de Investigaciones de la Altura, and Faculty of Sciences and Philosophy, Universidad Peruana Cayetano Heredia, Lima, Peru.
Maca is traditionally used for its nutritional and presumed medicinal properties. Maca is exported as powder, capsules, pills, flour, liquor, and extracts. There are different types of maca with differ-ent colors ranging from white to black. We have studied the pharmacological effects of 3 types; yellow, black, and red maca. Evidence from experimental studies indicates effects of maca on nutrition, fertility, memory, and mood. Black maca has better effects on sperm production than yellow maca which has only moderate effects. Red maca, however, has no effect on sperm production. However, red maca has been shown to reduce prostate size in rats in which prostate hyperplasia had been induced with testosterone enanthate; yellow maca has shown moderate effects here, whereas black maca has not shown any effects. Randomized clinical trials have shown that maca has favorable effects on energy and mood, may decrease anxiety and improve sexual desire. Maca has also been shown to improve sperm production, sperm motility, and semen volume. Serum levels of testosterone, estradiol, LH, FSH, and prolactin were not affected. The exact mechanisms of action are still unclear, but so far research clearly indicates that various bioactive constituents contribute to the clinical effects reported.