Product Information

Keywords: herpes, growth hormone, muscle strength, osteoporosis, fractures, insulin, hyperglycemia, anxiety


L-lysine is an ‘essential amino acid’ — that is, it is needed by the human body but not made there, and must be obtained from food or supplements. A male adult typically requires about 37 mg of L-lysine per day per kilogram of bodyweight1 — about 2.7 grams/day for someone weighing 73 kg (160 lbs). This is the amount needed to avoid lysine-deficiency ailments in a healthy person. More ambitious goals — beyond the mere avoidance of overt deficiencies — may require larger amounts than 37 mg/kg/day.

What we can’t tell you

In the U.S. and some other industrialized countries, government agencies like the U.S. Food and Drug Administration have adopted censorship as a method for intensifying their control over the supplement industry and its customers. Thus, FDA regulations prohibit us from telling you that any of our products are effective as medical treatments, even if they are, in fact, effective.

Accordingly, we will limit our discussion of L-Lysine to a brief summary of relevant research, and let you draw your own conclusions about what medical conditions it may be effective in treating.

L-lysine’s popularity as a nutritional supplement stems from studies suggesting that this amino acid decreases the recurrence rate of people infected with

  • herpes simplex virus.2

There is also published research suggesting that it is active against

  • osteoporosis2
  • anxiety8 and
  • insulin deficiency,15

and that it is useful in

  • increasing growth hormone levels11 and
  • increasing muscle strength.6

Let’s now examine the evidence for each of these effects.

Herpes viruses

Several clinical trials conducted in the 1980s showed that lysine supplementation at about 1000 mg three times per day reduced the frequency of herpes outbreaks and decreased the severity of symptoms associated with recurrences. Lower doses, down to about 1000 mg once per day, showed a lesser but measurable benefit.3,4,5

Other studies have shown that the herpes virus responds differently to different concentrations of the amino acids lysine and arginine. When the ratio of L-lysine to L-arginine is high, viral replication and the cytopathogenicity of herpes simplex virus have been found to be inhibited.2 This implies that to inhibit the herpes virus, arginine levels should be kept low.

Growth hormone (GH) and muscle strength

Dual amino-acid supplementation with L-lysine and L-arginine increases growth hormone levels without the need for large doses of either supplement. Studies using 1200-1500 mg of each supplement showed that significant increases in GH levels take place in the blood from 30 to 90 minutes after consumption.11,12 It appears that the best time to take arginine+lysine is when one is resting — not when one is about to exercise. Exercise itself causes growth hormone levels to rise, and the supplements do not push GH levels much higher than this.12 The implication of this evidence is that, with respect to GH levels, the supplement combination simulates the effects of exercise during non-exercise periods.

A clinical trial in which elderly women were given a daily supplement consisting of 1.5 g lysine + 5 g arginine + 2 g beta-hydroxy-beta-methylbutyrate (HMB) showed “a 17% improvement in the ‘get-up-and-go’ functionality test … increased limb circumference, leg strength, handgrip strength, and positive trends in fat-free mass.”6 The HMB part of the combination is thought to slow the breakdown of muscle protein7 — the lysine-arginine part is the muscle-growth component which is not dependent on HMB for its effects.

Osteoporosis and bone fractures

A therapeutic role of amino acids L-lysine (Lys) and L-arginine (Arg) in osteoporosis and fracture healing has been demonstrated both by cell culture studies and studies in lab animals.9,10,13 A clinical trial conducted in 1994 demonstrated “a more marked increment in BMD [bone mass density] in subjects treated with arginine-lysine-lactose, a greater reduction in painful symptoms ...” than in subjects treated with a lactose placebo.14

Despite these promising results of more than ten years ago, no further clinical trials have been conducted — neither by drug companies, nor through government funding — to develop Lysine/Arginine treatments for bone fractures or osteoporosis. The reasons are not hard to guess: Big Pharma is interested in developing blockbuster new drugs, not unpatentable supplements; and government medical research establishments are run by doctor-bureaucrats who oppose therapies that are available to patients without their having to visit doctors and ‘cross their palms with silver’ to get a prescription. But in the USA, thanks to the nutritional supplement act passed by Congress in 1994, people with bone fractures or osteoporosis can buy both L-lysine and L-arginine any time they want to. These are safe amino acid supplements that are far less expensive than prescription drugs, and require no time-consuming, wranglesome visits to over-priced physicians.

Insulin and hyperglycemia

Preliminary studies indicate that lysine consumption correlates with insulin responses — higher lysine consumption during a meal appears to stimulate insulin release.15 This work suggests that lysine supplementation at mealtime may improve the utilization of dietary sugars and fats, and discourage tissue-damaging episodes of hyperglycemia.


A recent study of 29 subjects with “relatively high trait anxiety” showed that dual supplementation with L-lysine and L-arginine (3 g each/day) caused a normalization of hormonal responses during psychosocial stress — i.e., the pattern of stress-related hormones that high-anxiety people experience during stressful experiencies (such as public speaking) was modified by the supplements so that it resembled that experienced by low-anxiety people.8


Are L-Lysine supplements useful for the conditions and purposes mentioned above? We aren’t allowed to tell you, so you should take a look at some of the references cited here, and then decide for yourself.

30160 500 mg 100 capsules 1-2 capsules $12.05
(7% off!)

Pronunciation: lysine læʹ·sēn

— RM

Last modified 2010.09.01