SAM-e reviews shared by users online suggest that this supplement may have benefits for mood, anxiety, joint pain, energy and motivation. Some users report that they did not experience any benefits from this supplement, but the majority describe positive results.
S-adenosylmethionine, also known as SAM-e, is a natural substance that is involved with a variety of functions in the body, such as the making of serotonin, dopamine and other brain chemicals. It also helps support immune function and healthy joints. SAM-e does not come from food. Instead, it is made in the body from amino acids.
The discovery of SAM-e occurred in 1952, and this chemical began being sold on the market as a dietary supplement in 1999. Researchers have conducted many studies on the effects of SAM-e for liver disease, depression and osteoarthritis, along with other conditions.
SAM-e is available in different forms, including capsules, tablets and liquids, at varying dosages ranging from 200 mg to 1,500 mg. Common uses of these supplements include managing depression, reducing anxiety, boosting energy levels and improving cognitive function.
SAM-e Reviews for Depression and Mood
SAM-e supplements are commonly used by consumers as a natural alternative to anti-depressant medications.
A number of studies have shown benefits for mood and the Natural Medicines Database rates SAM-e as Likely Effective for depression. However, the FDA has not approved the supplement as a treatment for depression.
Despite this, both the American Psychiatric Association and the Canadian Network for Mood and Anxiety Treatments recommend SAM-e as either a first-line or second-line treatment option for major depressive disorder.
Among product reviews left on Amazon, a large number of reviewers indicated that SAM-e is effective at reducing depression and elevating mood. Some reviewers claimed that SAM-e supplements work more effectively than antidepressants.
A small number of reviews indicated that SAM-e supplements did not affect depression, and some users reported experiencing headaches, sleepiness and stomach problems.
A 2009 critique published in Obstetrics and Gynecology Clinics of North America found that SAM-e began producing results faster than conventional antidepressants in a few different studies. Patients in these studies typically experienced a reduction in depression symptoms within 2 weeks or less.
A 2015 study published in the Journal of Multidisciplinary Healthcare showed that SAM-e used with betaine, which helps counteract potentially harmful effects, was effective at managing symptoms in those with mild to moderate depression. 
SAM-e can cause homocysteine levels to build up in the body, which can be harmful when there are inadequate levels of B vitamins. Betaine decreases this risk.
SAM-e Reviews for Anxiety and Stress
SAM-e supplements are also used to manage anxiety or reduce stress. However, there is less research available looking at its effects on anxiety. More studies are needed to rate its efficacy for these uses.
There are consumer reviews of SAM-e for anxiety which suggest a benefit, but these reviews could be subject to a placebo effect.
On Amazon.com, a large percentage of consumers who take SAM-e for this purpose reported that it is effective at easing stress and anxiety.
A small percentage of those who take SAM-e for anxiety and stress reported that it does not lower stress levels or reduce anxiety. Some of these consumers also experienced gastrointestinal problems when taking these supplements.
So, does SAM-e work for anxiety or not? Studies focusing on the effects of SAM-e on anxiety have not been as numerous as those that focus on depression.
A 2013 literature review published in the Journal of Neuropsychiatric Disease and Treatment found that SAM-e produced a 70 percent reduction in anxiety and depression among women with postpartum depression. 
SAM-e Reviews for Energy and Cognitive Function
Several SAM-e products claim to boost energy levels and improve cognitive function. A large percentage of SAM-e 400mg tablet reviews state that these products are effective at increasing energy and improving memory, concentration and other aspects of cognitive function.
A small percentage of reviews for these products stated that energy levels stayed the same or decreased and there were no changes in cognitive function.
Very few studies have focused on the effects of SAM-e on cognitive function and energy. One 2013 study that appeared in PLoS One showed that SAM-e improved cognitive performance in mice and theorized that this supplement might help improve spatial memory in patients with dementia. 
SAM-e Safety Review
According to the Mayo Clinic, supplements with SAM-e are typically safe to take for up to 2 years in doses that range from 400 to 600 mg. 
Large doses of SAM-e should not be taken, since they can cause mania. Those with bipolar disorder should not take SAM-e supplements due to an increased risk of causing manic episodes to become worse.
SAM-e is rated as Possibly Safe for pregnant women when used intravenously for short periods of time during the third trimester of pregnancy. Its use at other times in pregnancy has not yet been studied, nor has it been studied for its safety during lactation.
If you are pregnant or nursing, consult with a doctor to determine whether this supplement is safe for you to take or not. According to the NMD, “Use of SAMe in pregnancy should only be considered when benefits clearly outweigh the potential risks.”
SAM-e supplements can cause other side effects when taken in smaller doses, although these are generally mild. Some of these potential side effects include dry mouth, dizziness, diarrhea, headache and nausea.
Some people experience anxiety as a side effect of taking SAM-e. Those who have an anxiety disorder should only take these supplements under the guidance of their doctor due to the risk of this side effect, which can make their symptoms worse.
SAM-e supplements should only be taken during the day. Taking them at night can interfere with sleep, since these supplements can cause heart palpitations or difficulty sleeping.
Those who take antidepressants should discuss using SAM-e with their doctor. SAM-e has the potential to interact with these medications and raise the risk of a condition called serotonin syndrome, which occurs when the body has too much of this brain chemical.
SAM-e can also interact with other medications that boost serotonin production, such as tramadol and pentazocine. It also has potential interactions with diabetes medications. Consumers who use these medications should talk to their doctor first before using SAM-e products.
While SAM-e reviews can help consumers evaluate these products better based on other users’ experiences, a doctor should be consulted to determine if it is safe to take.